We Keep Coding

javascript: I need to get an object key from the function argument

vm.contributorAmountPerYear[index-1] gets me an object, and I want its key to be the year argument of the function.
function getAgriAmount(year,amount,index) {
if (typeof amount !== "number" ) {
amount = parseInt(amount ||0);
};
var argiYearlyLocalCost = vm.argiterraYearlyLocalCost;
console.log(vm.contributorAmountPerYear[index-1].year);
}

vm.contributorAmountPerYear[index-1][year]

For any javascript object, you should keep in mind that if you use . dot notation, you cannot access the properties for keys that come from a variable and are determined at runtime. Use square bracket notation [] for such a case. This should work:
vm.contributorAmountPerYear[index-1][year];
Dot notation should be used when you already know the key:
var cuteJavaScriptObject = {
animal : 'cat'
}
var myVar = 'animal';
console.log(cuteJavaScriptObject.animal); // OK
console.log(cuteJavaScriptObject.myVar); // Wrong !!
console.log(cuteJavaScriptObject[myVar]); // Now OK

jQuery param dynamic object name

why can't i have a variable in an object? I get an error like:
"Uncaught SyntaxError: Unexpected token this"
My code is like this.
$("#search_options input:checkbox").on('click', function() {
var params = {
$(this).attr('name') : $(this).val(),
};
var str = jQuery.param(params);
});
I'm sure that $(this) is working because I tried to console.log it outside the params object then i is working.

Object literals cannot have variable property names. You'll have to assign the property like so:
...
var params = {};
params[$(this).attr('name')] = $(this).val();
var str = jQuery.param(params);

If you want to use value of a variable as a property name, you must use this syntax:
var params = {}
params[$(this).attr('name')] = $(this).val();
The literal notation, that you're trying to use, expects property name to be a valid JavaScript identifier.

get/set for all available properties (JS)

Is it possible to create get/set function for undefined properties,
like in PHP __get() and __set() ?

You can access JavaScript object properties values using array access notation, you can also create a new property at any time using this notation or regular assignment notation.
var myObject = {};
myObject.Name = "Luis";
alert(myObject.Name);
alert(myObject["Name"]);
myObject["Name"] = "Dany";
alert(myObject.Name);

You can do
function ClassName(arg) {
var v = arg;
this.getter = function {
return v;
};
this.setter = function(val) {
v = val;
};
}
when you use it
var cn = new ClassName('a');
cn.setter('b');
alert(cn.getter()); /* alerts value 'b' */
Note that this uses the Constructor Invocation Pattern. By convention, you need to declare the function/class name with capital letter to indicate that this function/class need to be declared with the 'new' keyword.
Hope this helps

How to set a Javascript object values dynamically?

It's difficult to explain the case by words, let me give an example:
var myObj = {
'name': 'Umut',
'age' : 34
};
var prop = 'name';
var value = 'Onur';
myObj[name] = value; // This does not work
eval('myObj.' + name) = value; //Bad coding ;)
How can I set a variable property with variable value in a JavaScript object?

myObj[prop] = value;
That should work. You mixed up the name of the variable and its value. But indexing an object with strings to get at its properties works fine in JavaScript.

myObj.name=value
or
myObj['name']=value (Quotes are required)
Both of these are interchangeable.
Edit: I'm guessing you meant myObj[prop] = value, instead of myObj[name] = value. Second syntax works fine: http://jsfiddle.net/waitinforatrain/dNjvb/1/

You can get the property the same way as you set it.
foo = {
bar: "value"
}
You set the value
foo["bar"] = "baz";
To get the value
foo["bar"]
will return "baz".

You could also create something that would be similar to a value object (vo);
SomeModelClassNameVO.js;
function SomeModelClassNameVO(name,id) {
this.name = name;
this.id = id;
}
Than you can just do;
var someModelClassNameVO = new someModelClassNameVO('name',1);
console.log(someModelClassNameVO.name);

simple as this
myObj.name = value;

When you create an object myObj as you have, think of it more like a dictionary. In this case, it has two keys, name, and age.
You can access these dictionaries in two ways:
Like an array (e.g. myObj[name]); or
Like a property (e.g. myObj.name); do note that some properties are reserved, so the first method is preferred.
You should be able to access it as a property without any problems. However, to access it as an array, you'll need to treat the key like a string.
myObj["name"]
Otherwise, javascript will assume that name is a variable, and since you haven't created a variable called name, it won't be able to access the key you're expecting.

You could do the following:
var currentObj = {
name: 'Umut',
age : 34
};
var newValues = {
name: 'Onur',
}
Option 1:
currentObj = Object.assign(currentObj, newValues);
Option 2:
currentObj = {...currentObj, ...newValues};
Option 3:
Object.keys(newValues).forEach(key => {
currentObj[key] = newValues[key];
});

Determine original name of variable after its passed to a function

I've got a feeling this might not be possible, but I would like to determine the original variable name of a variable which has been passed to a function in javascript. I don't know how to explain it any better than that, so see if this example makes sense.
function getVariableName(unknownVariable){
return unknownVariable.originalName;
}
getVariableName(foo); //returns string "foo";
getVariableName(bar); //returns string "bar";
This is for a jquery plugin i'm working on, and i would like to be able to display the name of the variable which is passed to a "debug" function.

You're right, this is very much impossible in any sane way, since only the value gets passed into the function.

This is now somehow possible thanks to ES6:
function getVariableName(unknownVariableInAHash){
return Object.keys(unknownVariableInAHash)[0]
}
const foo = 42
const bar = 'baz'
console.log(getVariableName({foo})) //returns string "foo"
console.log(getVariableName({bar})) //returns string "bar"
The only (small) catch is that you have to wrap your unknown variable between {}, which is no big deal.

As you want debugging (show name of var and value of var),
I've been looking for it too, and just want to share my finding.
It is not by retrieving the name of the var from the var but the other way around : retrieve the value of the var from the name (as string) of the var.
It is possible to do it without eval, and with very simple code, at the condition you pass your var into the function with quotes around it, and you declare the variable globally :
foo = 'bar';
debug('foo');
function debug(Variable) {
var Value = this[Variable]; // in that occurrence, it is equivalent to
// this['foo'] which is the syntax to call the global variable foo
console.log(Variable + " is " + Value); // print "foo is bar"
}

Well, all the global variables are properties of global object (this or window), aren't they?
So when I wanted to find out the name of my variables, I made following function:
var getName = function(variable) {
for (var prop in window) {
if (variable === window[prop]) {
return prop;
}
}
}
var helloWorld = "Hello World!";
console.log(getName(helloWorld)); // "helloWorld"
Sometimes doesn't work, for example, if 2 strings are created without new operator and have the same value.

Global w/string method
Here is a technique that you can use to keep the name and the value of the variable.
// Set up a global variable called g
var g = {};
// All other variables should be defined as properties of this global object
g.foo = 'hello';
g.bar = 'world';
// Setup function
function doStuff(str) {
if (str in g) {
var name = str;
var value = g[str];
// Do stuff with the variable name and the variable value here
// For this example, simply print to console
console.log(name, value);
} else {
console.error('Oh snap! That variable does not exist!');
}
}
// Call the function
doStuff('foo'); // log: foo hello
doStuff('bar'); // log: bar world
doStuff('fakeVariable'); // error: Oh snap! That variable does not exist!
This is effectively creating a dictionary that maps variable names to their value. This probably won't work for your existing code without refactoring every variable. But using this style, you can achieve a solution for this type of problem.
ES6 object method
In ES6/ES2015, you are able to initialize an object with name and value which can almost achieve what you are trying to do.
function getVariableName(unknownVariable) {
return Object.keys(unknownVariable)[0];
}
var foo = 'hello';
var output = getVariableName({ foo }); // Note the curly brackets
console.log(output);
This works because you created a new object with key foo and value the same as the variable foo, in this case hello. Then our helper method gets the first key as a string.
Credit goes to this tweet.

Converting a set of unique variable into one JSON object for which I wrote this function
function makeJSON(){ //Pass the variable names as string parameters [not by reference]
ret={};
for(i=0; i<arguments.length; i++){
eval("ret."+arguments[i]+"="+arguments[i]);
}
return ret;
}
Example:
a=b=c=3;
console.log(makeJSON('a','b','c'));
Perhaps this is the reason for this query

I think you can use
getVariableName({foo});

Use a 2D reference array with .filter()
Note: I now feel that #Offermo's answer above is the best one to use. Leaving up my answer for reference, though I mostly wouldn't recommend using it.
Here is what I came up with independently, which requires explicit declaration of variable names and only works with unique values. (But will work if those two conditions are met.)
// Initialize some variables
let var1 = "stick"
let var2 = "goo"
let var3 = "hello"
let var4 = "asdf"
// Create a 2D array of variable names
const varNames = [
[var1, "var1"],
[var2, "var2"],
[var3, "var3"]
]
// Return either name of variable or `undefined` if no match
const getName = v => varNames.filter(name => name[0] === v).length
? varNames.filter(name => name[0] === v)[0][1]
: undefined
// Use `getName` with OP's original function
function getVariableName(unknownVariable){
return getName(unknownVariable)
}

This is my take for logging the name of an input and its value at the same time:
function logVariableAndName(unknownVariable) {
const variableName = Object.keys(unknownVariable)[0];
const value = unknownVariable[variableName];
console.log(variableName);
console.log(value);
}
Then you can use it like logVariableAndName({ someVariable })