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Angular - Should I use local variable or this.variable

I was looking for this but could not find a question as simple as I want it. The problem is really simple: In angular js, should I use local variables, or properties of this (in cases when I don't need to use this).
Example:
// I need "this" here because I need this collection in template
this.collection = SomeService.fetchCollection();
// I can use either "foo" or "this.foo" here, which one is better?
this.fetchSomeData = function(type) {
var foo = AnotherService.foo(type);
return FooService.call(foo);
}

A local variable, so it can be cleaned up as soon as the method exits. Otherwise it would stay unused in the parent's namespace.
But in 99% of cases that will have no real-world effect, so it doesn't matter.

Because you haven't declared 'foo' as a var it will be a global here, which is bad. You should at least prefix it with 'var' so it's scoped to the function and not globally; it shouldn't be available outside the function.

in my opinion it is a good practice not to reveal everything and keep it encapsulated - for example, it avoids moving logic to view which is bad
also, consider that you have a for loop iteration over i variable - would you also use this.i for such purpose?

Get the current scope of a Javascript Function [duplicate]

When I call a function, a local scope is erected for that call. Is there any way to directly reference that scope as an object? Just like window is a reference for the global scope object.
Example:
function test(foo){
var bar=1
//Now, can I access the object containing foo, bar, arguments and anything
//else within the local scope like this:
magicIdentifier.bar
}
Alternately, does anyone have a complete list of what is in the local scope on top of custom variables?
Background: I'm trying to get down to a way of completely shifting to global scope from within a function call, the with statement is a joke, call works a little better, but it still breaks for anything declared in function scope but not in global scope, therefore I would declare these few cases in global scope, but that requires me to know what they are. The IE function execScript makes a complete shift, but that only solves the problem for IE.
Note: To anyone loading JavaScript dynamically, setTimeout(code,1) is a simple effective hack to achieve global scope, but it will not execute immediately.

No, there's no way to reference the variable object of the execution context of a function binding object of the variable environment of the execution context (that's what that thing is called [now; hence the strikethrough]; details in §10.3 of the specification). You can only access the limited view to it you get with arguments (which is very limited indeed).
Usually when I've wanted to do this, I've just put everything I wanted on an object and then used that (e.g., passed it into a function). Of course, any functions created within the context have access to everything in scope where they're created, as they "close over" the context; more: Closures are not complicated.

I know this is hugely late, and you're probably not even slightly interested any more, but I was interested in the feasibility of this too and you should be able to make a work around of some sort using:
(function(global) {
var testVar = 1;
global.scope = function(s) {
return eval(s);
}
})(this);
then running:
scope('testVar'); // 1
returns the variable from within the closure. Not particularly nice, but theoretically possible to wrap that in an object, perhaps using some validation and getters and setters if you needed?
Edit: Having re-read the question, I assume you'd want to access it without having to specify a function in the scope itself, so this probably isn't applicable. I'll leave this here anyway.

Certain versions of Netscape had a magic property in the arguments object that did what you're looking for. (I can't remember what it was called)

What about something like this?
<script type="text/javascript">
var test = {
bar : 1,
foo : function () {
alert(this.bar);
}
}
test.foo();
</script>

You don't need a keyword to reference a variable in the local scope, because it's the scope you're in.

JavaScript identifiers not to use

I just found out the hard way that naming your variable arguments is a bad idea.
var arguments = 5;
(function () {
console.log(arguments);
})();
Output: []
It turns out that arguments is "a local variable available within all functions" so in each new execution context, arguments is shadowed.
My question is: Are there any other such treacherous names which, like arguments, are not true reserved words, but will cause still problems?

Yes. Like window or document, for example. See a longer list here ("other javascript keywords").
Wouldn't recommend using any of them, even though some would work as intended.
Edit: Like mentioned in javascript.about.com, "While they are not reserved words, the use of those words as variables and functions should be avoided.". They are listing mostly the same things classified as predefined classes and objects and global properties.
Example of a problem:
var window = 5;
(function () {
alert(window);
})();
the code above has unpredictable results due to fact that window is the word to refer to the window object. Firefox prevents modifications to it, so alert will still refer to window object, whereas in IE8, you'll get alert with value 5.

There are no other automatic symbols inside functions (apart from this, but you cannot create a variable with that name anyway), if that's what you mean. But there are a couple of default global variables, so defining a variable with the same name inside the function will shadow the global variable.

You can get a list of all names used in the global namespace, by executing this in the console:
var t = [];
for(v in this){t.push(v)}
console.log(t.sort());
Result:
["$","ArrayBuffer","Attr","Audio","AudioProcessingEvent","BeforeLoadEvent","Blob","CDATASection","CSSCharsetRule","CSSFontFaceRule","CSSImportRule","CSSMediaRule","CSSPageRule","CSSPrimitiveValue","CSSRule","CSSRuleList","CSSStyleDeclaration","CSSStyleRule","CSSStyleSheet","CSSValue","CSSValueList","CTIsPlayback","CanvasGradient","CanvasPattern","CanvasRenderingContext2D","CharacterData","ClientRect","ClientRectList","Clipboard","CloseEvent","Comment","CompositionEvent","Counter","CustomEvent","DOMException","DOMImplementation","DOMParser","DOMSettableTokenList","DOMStringList","DOMStringMap","DOMTokenList","DataView","DeviceOrientationEvent","Document","DocumentFragment","DocumentType","Element","Entity","EntityReference","ErrorEvent","Event","EventEmitter","EventException","EventSource","File","FileError","FileList","FileReader","Float32Array","Float64Array","FormData","Generator","HTMLAllCollection","HTMLAnchorElement","HTMLAppletElement","HTMLAreaElement","HTMLAudioElement","HTMLBRElement","HTMLBaseElement","HTMLBaseFontElement","HTMLBodyElement","HTMLButtonElement","HTMLCanvasElement","HTMLCollection","HTMLDListElement","HTMLDataListElement","HTMLDirectoryElement","HTMLDivElement","HTMLDocument","HTMLElement","HTMLEmbedElement","HTMLFieldSetElement","HTMLFontElement","HTMLFormElement","HTMLFrameElement","HTMLFrameSetElement","HTMLHRElement","HTMLHeadElement","HTMLHeadingElement","HTMLHtmlElement","HTMLIFrameElement","HTMLImageElement","HTMLInputElement","HTMLKeygenElement","HTMLLIElement","HTMLLabelElement","HTMLLegendElement","HTMLLinkElement","HTMLMapElement","HTMLMarqueeElement","HTMLMediaElement","HTMLMenuElement","HTMLMetaElement","HTMLMeterElement","HTMLModElement","HTMLOListElement","HTMLObjectElement","HTMLOptGroupElement","HTMLOptionElement","HTMLOutputElement","HTMLParagraphElement","HTMLParamElement","HTMLPreElement","HTMLProgressElement","HTMLQuoteElement","HTMLScriptElement","HTMLSelectElement","HTMLSourceElement","HTMLSpanElement","HTMLStyleElement","HTMLTableCaptionElement","HTMLTableCellElement","HTMLTableColElement","HTMLTableElement","HTMLTableRowElement","HTMLTableSectionElement","HTMLTextAreaElement","HTMLTitleElement","HTMLTrackElement","HTMLUListElement","HTMLUnknownElement","HTMLVideoElement","HashChangeEvent","IceCandidate","Image","ImageData","Int16Array","Int32Array","Int8Array","KeyboardEvent","Markdown","MediaController","MediaError","MediaList","MediaStreamEvent","MessageChannel","MessageEvent","MessagePort","MimeType","MimeTypeArray","MouseEvent","MutationEvent","NamedNodeMap","Node","NodeFilter","NodeList","Notation","Notification","OfflineAudioCompletionEvent","Option","OverflowEvent","PERSISTENT","PR","PR_SHOULD_USE_CONTINUATION","PageTransitionEvent","Plugin","PluginArray","PopStateEvent","ProcessingInstruction","ProgressEvent","RGBColor","RTCIceCandidate","RTCSessionDescription","Range","RangeException","Rect","SQLException","SVGAElement","SVGAltGlyphDefElement","SVGAltGlyphElement","SVGAltGlyphItemElement","SVGAngle","SVGAnimateColorElement","SVGAnimateElement","SVGAnimateMotionElement","SVGAnimateTransformElement","SVGAnimatedAngle","SVGAnimatedBoolean","SVGAnimatedEnumeration","SVGAnimatedInteger","SVGAnimatedLength","SVGAnimatedLengthList","SVGAnimatedNumber","SVGAnimatedNumberList","SVGAnimatedPreserveAspectRatio","SVGAnimatedRect","SVGAnimatedString","SVGAnimatedTransformList","SVGCircleElement","SVGClipPathElement","SVGColor","SVGComponentTransferFunctionElement","SVGCursorElement","SVGDefsElement","SVGDescElement","SVGDocument","SVGElement","SVGElementInstance","SVGElementInstanceList","SVGEllipseElement","SVGException","SVGFEBlendElement","SVGFEColorMatrixElement","SVGFEComponentTransferElement","SVGFECompositeElement","SVGFEConvolveMatrixElement","SVGFEDiffuseLightingElement","SVGFEDisplacementMapElement","SVGFEDistantLightElement","SVGFEDropShadowElement","SVGFEFloodElement","SVGFEFuncAElement","SVGFEFuncBElement","SVGFEFuncGElement","SVGFEFuncRElement","SVGFEGaussianBlurElement","SVGFEImageElement","SVGFEMergeElement","SVGFEMergeNodeElement","SVGFEMorphologyElement","SVGFEOffsetElement","SVGFEPointLightElement","SVGFESpecularLightingElement","SVGFESpotLightElement","SVGFETileElement","SVGFETurbulenceElement","SVGFilterElement","SVGFontElement","SVGFontFaceElement","SVGFontFaceFormatElement","SVGFontFaceNameElement","SVGFontFaceSrcElement","SVGFontFaceUriElement","SVGForeignObjectElement","SVGGElement","SVGGlyphElement","SVGGlyphRefElement","SVGGradientElement","SVGHKernElement","SVGImageElement","SVGLength","SVGLengthList","SVGLineElement","SVGLinearGradientElement","SVGMPathElement","SVGMarkerElement","SVGMaskElement","SVGMatrix","SVGMetadataElement","SVGMissingGlyphElement","SVGNumber","SVGNumberList","SVGPaint","SVGPathElement","SVGPathSeg","SVGPathSegArcAbs","SVGPathSegArcRel","SVGPathSegClosePath","SVGPathSegCurvetoCubicAbs","SVGPathSegCurvetoCubicRel","SVGPathSegCurvetoCubicSmoothAbs","SVGPathSegCurvetoCubicSmoothRel","SVGPathSegCurvetoQuadraticAbs","SVGPathSegCurvetoQuadraticRel","SVGPathSegCurvetoQuadraticSmoothAbs","SVGPathSegCurvetoQuadraticSmoothRel","SVGPathSegLinetoAbs","SVGPathSegLinetoHorizontalAbs","SVGPathSegLinetoHorizontalRel","SVGPathSegLinetoRel","SVGPathSegLinetoVerticalAbs","SVGPathSegLinetoVerticalRel","SVGPathSegList","SVGPathSegMovetoAbs","SVGPathSegMovetoRel","SVGPatternElement","SVGPoint","SVGPointList","SVGPolygonElement","SVGPolylineElement","SVGPreserveAspectRatio","SVGRadialGradientElement","SVGRect","SVGRectElement","SVGRenderingIntent","SVGSVGElement","SVGScriptElement","SVGSetElement","SVGStopElement","SVGStringList","SVGStyleElement","SVGSwitchElement","SVGSymbolElement","SVGTRefElement","SVGTSpanElement","SVGTextContentElement","SVGTextElement","SVGTextPathElement","SVGTextPositioningElement","SVGTitleElement","SVGTransform","SVGTransformList","SVGUnitTypes","SVGUseElement","SVGVKernElement","SVGViewElement","SVGViewSpec","SVGZoomAndPan","SVGZoomEvent","Selection","SessionDescription","SharedWorker","SpeechInputEvent","StackExchange","Storage","StorageEvent","StyleSheet","StyleSheetList","TEMPORARY","Text","TextEvent","TextMetrics","TextTrack","TextTrackCue","TextTrackCueList","TextTrackList","TimeRanges","TouchEvent","TrackEvent","UIEvent","URL","Uint16Array","Uint32Array","Uint8Array","Uint8ClampedArray","WebGLActiveInfo","WebGLBuffer","WebGLContextEvent","WebGLFramebuffer","WebGLProgram","WebGLRenderbuffer","WebGLRenderingContext","WebGLShader","WebGLShaderPrecisionFormat","WebGLTexture","WebGLUniformLocation","WebKitAnimationEvent","WebKitBlobBuilder","WebKitCSSFilterValue","WebKitCSSKeyframeRule","WebKitCSSKeyframesRule","WebKitCSSMatrix","WebKitCSSRegionRule","WebKitCSSTransformValue","WebKitIntent","WebKitMediaSource","WebKitMutationObserver","WebKitPoint","WebKitSourceBuffer","WebKitSourceBufferList","WebKitTransitionEvent","WebSocket","WheelEvent","Window","WinterBash","Worker","XMLDocument","XMLHttpRequest","XMLHttpRequestException","XMLHttpRequestProgressEvent","XMLHttpRequestUpload","XMLSerializer","XPathEvaluator","XPathException","XPathResult","XSLTProcessor","__qc","_gaq","_gat","_qevents","addEventListener","alert","apiCallbacks","applicationCache","atob","blur","btoa","captureEvents","careers_adselector","careers_adurl","careers_companycssurl","careers_cssurl","careers_leaderboardcssurl","chrome","clearInterval","clearTimeout","clientInformation","close","closed","confirm","console","crypto","defaultStatus","defaultstatus","devicePixelRatio","dispatchEvent","document","event","external","find","focus","frameElement","frames","gaGlobal","gauth","genuwine","getComputedStyle","getMatchedCSSRules","getSelection","history","i","initFadingHelpText","initTagRenderer","innerHeight","innerWidth","jQuery","jQuery171005593172716908157_1357215797040","jQuery171005593172716908157_1357215797041","length","localStorage","location","locationbar","matchMedia","menubar","moveBy","moveScroller","moveTo","name","navigator","offscreenBuffering","onabort","onbeforeunload","onblur","oncanplay","oncanplaythrough","onchange","onclick","oncontextmenu","ondblclick","ondeviceorientation","ondrag","ondragend","ondragenter","ondragleave","ondragover","ondragstart","ondrop","ondurationchange","onemptied","onended","onerror","onfocus","onhashchange","oninput","oninvalid","onkeydown","onkeypress","onkeyup","onload","onloadeddata","onloadedmetadata","onloadstart","onmessage","onmousedown","onmousemove","onmouseout","onmouseover","onmouseup","onmousewheel","onoffline","ononline","onpagehide","onpageshow","onpause","onplay","onplaying","onpopstate","onprogress","onratechange","onreset","onresize","onscroll","onsearch","onseeked","onseeking","onselect","onstalled","onstorage","onsubmit","onsuspend","ontimeupdate","onunload","onvolumechange","onwaiting","onwebkitanimationend","onwebkitanimationiteration","onwebkitanimationstart","onwebkittransitionend","open","openDatabase","opener","outerHeight","outerWidth","pageXOffset","pageYOffset","parent","performance","personalbar","postMessage","prepareEditor","prettyPrint","prettyPrintOne","print","profileLink","prompt","quantserve","releaseEvents","removeEventListener","resizeBy","resizeTo","sanitizeAndSplitTags","screen","screenLeft","screenTop","screenX","screenY","scriptSrc","scroll","scrollBy","scrollTo","scrollX","scrollY","scrollbars","self","sessionStorage","setInterval","setTimeout","showFadingHelpText","showModalDialog","status","statusbar","stop","styleCode","styleMedia","t","tagRenderer","tagRendererRaw","toolbar","top","uh","v","v8Intl","votesCast","webkitAudioContext","webkitAudioPannerNode","webkitCancelAnimationFrame","webkitCancelRequestAnimationFrame","webkitConvertPointFromNodeToPage","webkitConvertPointFromPageToNode","webkitIDBCursor","webkitIDBDatabase","webkitIDBDatabaseException","webkitIDBFactory","webkitIDBIndex","webkitIDBKeyRange","webkitIDBObjectStore","webkitIDBRequest","webkitIDBTransaction","webkitIndexedDB","webkitIntent","webkitMediaStream","webkitNotifications","webkitPostMessage","webkitRTCPeerConnection","webkitRequestAnimationFrame","webkitRequestFileSystem","webkitResolveLocalFileSystemURL","webkitStorageInfo","webkitURL","window"];
So, these can't / shouldn't be used (at least in Google Chrome), in the global scope. If you declare them as variables in a local scope, you're fine.
This won't contain all names used, however, since arguments is only available in the function scope, for example.
Note: this function does return all global variables from your libraries, also

JavaScript Closures use global setting object or pass it to each function

another question concerning javascricpt closures. I have a global "settings object". Is it better to use it from within functions in global scope or pass the object every time a function needs to access the object?
For a better understanding a little mockup of the situation here
Please ignore that "baz()" also gets the passed object within "foobar()" from the global scope within the closure. You see that both versions work fine.
The thing is that I am passing whatever object the function needs to work to every function and EVERY time (unneccesary overhead?), which might be nice and easy to read/understand but I am seriously thinking about changing this. Disadvantage would be that I have to keep the "this" scope wherever it gets deeper right?
Thanks for your advice!

Your settings object isn't global, it's defined within a closure.
As the intent is that it be accessed by other function within the closure, I'd say you were 100% fine to just access that object directly and not pass it as a parameter.
FWIW, even if you did pass it as a parameter the overhead is negligible because only a reference to the object is passed, not a copy of the whole object.

So you have basically three options:
You want to expose settings as a global variable, and have it accessed by your functions,
You want to hide settings as an implementation detail and have it accessed by your functions,
You want to give a possibility to supply different settings objects to different functions.
Global variable approach
Well, I guess it's a little bit like with any global variable. If settings is a singleton (for example it describes your application) and you can't see any benefit in having a possibility to call the same function with different settings objects, then I don't see why it couldn't be a global variable.
That said, because of all the naming conflicts, in Javascript it's good to "namespace" all the global variables. So instead of global variables foo and bar you should rather have one global variable MyGlobalNamespace which is an objects having attributes: MyGlobalNamespace.foo and MyGlobalNamespace.bar.
Private variable approach
Having a private variable accessed by a closure is a good pattern for hiding implementation details. If the settings object is something you don't want to expose as an API, this is probably the right choice.
Additional function parameter approach
Basically if you see a gain in having a possibility of supplying different settings to different function calls. Or perhaps if you can picture such gain in the future. Obvious choice if you have many instances of settings in your application.
EDIT
As to the question from the comments:
Example 1)
var blah = 123;
function fizbuzz() {
console.log(blah); // <-- This is an example of a closure accessing
// a variable
console.log(this.blah); // <-- Most likely makes no sense. It might work,
// because by default this will be set to a global
// object named window, but this is probably not
// what you want. In other situations this might
// point to another object.
}
Example 2)
var obj = {
blah: 123,
fizbuzz: function() {
console.log(this.blah); // <-- This is *NOT* an example of a closure
// accessing a private variable. It's rather the
// closest Javascript can get to accessing an
// instance variable by a method, though this
// terminology shouldn't be used.
console.log(blah); // <-- This MAKES NO SENSE, there is no variable blah
// accessible from here.
}
};
In a nutshell, I'd encourage you to read some good book on the fundamental concepts of Javascript. It has its paculiarities and it's good to know them.

JavaScript: Reference a functions local scope as an object

When I call a function, a local scope is erected for that call. Is there any way to directly reference that scope as an object? Just like window is a reference for the global scope object.
Example:
function test(foo){
var bar=1
//Now, can I access the object containing foo, bar, arguments and anything
//else within the local scope like this:
magicIdentifier.bar
}
Alternately, does anyone have a complete list of what is in the local scope on top of custom variables?
Background: I'm trying to get down to a way of completely shifting to global scope from within a function call, the with statement is a joke, call works a little better, but it still breaks for anything declared in function scope but not in global scope, therefore I would declare these few cases in global scope, but that requires me to know what they are. The IE function execScript makes a complete shift, but that only solves the problem for IE.
Note: To anyone loading JavaScript dynamically, setTimeout(code,1) is a simple effective hack to achieve global scope, but it will not execute immediately.

No, there's no way to reference the variable object of the execution context of a function binding object of the variable environment of the execution context (that's what that thing is called [now; hence the strikethrough]; details in §10.3 of the specification). You can only access the limited view to it you get with arguments (which is very limited indeed).
Usually when I've wanted to do this, I've just put everything I wanted on an object and then used that (e.g., passed it into a function). Of course, any functions created within the context have access to everything in scope where they're created, as they "close over" the context; more: Closures are not complicated.

I know this is hugely late, and you're probably not even slightly interested any more, but I was interested in the feasibility of this too and you should be able to make a work around of some sort using:
(function(global) {
var testVar = 1;
global.scope = function(s) {
return eval(s);
}
})(this);
then running:
scope('testVar'); // 1
returns the variable from within the closure. Not particularly nice, but theoretically possible to wrap that in an object, perhaps using some validation and getters and setters if you needed?
Edit: Having re-read the question, I assume you'd want to access it without having to specify a function in the scope itself, so this probably isn't applicable. I'll leave this here anyway.

Certain versions of Netscape had a magic property in the arguments object that did what you're looking for. (I can't remember what it was called)

What about something like this?
<script type="text/javascript">
var test = {
bar : 1,
foo : function () {
alert(this.bar);
}
}
test.foo();
</script>

You don't need a keyword to reference a variable in the local scope, because it's the scope you're in.