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Javascript: given an array of variables, function to remove characters and output another array

so I am still learning Javascript, so I know this is a basic questions, and I'd really like to learn what I'm missing. I have an array of variables, and I need a function that removes special characters, and returns the result as an array.
Here's my code:
var myArray = [what_hap, desc_injury];
function ds (string) {
string.replace(/[\\]/g, ' ')
string.replace(/[\"]/g, ' ')
string.replace(/[\/]/g, '-')
string.replace(/[\b]/g, ' ')
string.replace(/[\f]/g, ' ')
string.replace(/[\n]/g, ',')
string.replace(/[\r]/g, ' ')
string.replace(/[\t]/g, ' ');
return string;
}
ds (myArray);
I know that's not going to work, so I'm just trying to learn the simplest and cleanest way to output:
[whatHap: TEXTw/oSpecialCharacters, descInj: TEXTw/oSpecialCharacters]
Anyone willing to guide a noobie? Thanks! :)

The comments on the question are correct, you need to specify what you are asking a little better but I will try and give you some guidance from what I assume about your intended result.
One important thing to note which would fix the function you already have is that string.replace() will not change the string itself, it returns a new string with the replacements as you can see in the documentation. to do many replacements you need to do string = string.replace('a', '-')
On to a solution for the whole array. There are a couple ways to process an array in javascript: for loop, Array.forEach(), or Array.map(). I urge you to read the documentation of each and look up examples on your own to understand each and where they are most useful.
Since you want to replace everything in your array I suggest using .map()
or .foreach() since these will loop through the whole array for you without you having to keep track of the index yourself. Below are examples of using each to implement what I think you are going for.
Map
function removeSpecial(str) {
// replace all these character with ' '
// \ " \b \f \r \t
str = str.replace(/[\\"\b\f\r\t]/g, ' ');
// replace / with -
str = str.replace(/\//g, '-');
// replace \n with ,
str = str.replace(/\n/g, ',');
return str;
}
let myArray = ["string\\other", "test/path"];
let withoutSpecial = myArray.map(removeSpecial); // ["string other", "test-path"]
forEach
function removeSpecial(myArray) {
let withoutSpecial = [];
myArray.forEach(function(str) {
str = str.replace(/[\\"\b\f\r\t]/g, ' ');
// replace / with -
str = str.replace(/\//g, '-');
// replace \n with ,
str = str.replace(/\n/g, ',');
withoutSpecial.push(str)
});
return withoutSpecial;
}
let myArray = ["string\\other", "test/path"];
let withoutSpecial = removeSpecial(myArray); // ["string other", "test-path"]
The internalals of each function's can be whatever replacements you need it to be or you could replace them with the function you already have. Map is stronger in this situation because it will replace the values in the array, it's used to map the existing values to new corresponding values one to one for every element. On the other hand the forEach solution requires you to create and add elements to a new array, this is better for when you need to do something outside the array itself for every element in the array.
PS. you should check out https://regex101.com/ for help building regular expressions if you want a more complex replacements but you dont really need them for this situation

I realize that the way I wrote my goal isn't exactly clear. I think what I should have said was that given several text strings, I want to strip out some specific characters (quotes, for example), and then output each of those into an array that can be accessed. I have read about arrays, it's just been my experience in learning JS that reading code and actually doing code are two very different things.
So I appreciate the references to documentation, what I really needed to see was a real life example code.
I ended up finding a solution that works:
function escapeData(data) {
return data
.replace(/\r/g, "");
}
var result = {};
result.what_hap_escaped = escapeData($what_hap);
result.desc_injury_escaped = escapeData($desc_injury);
result;
I appreciate everyone's time, and hope I didn't annoy you guys too much with my poorly constructed question :)

How to find a substring only in the text portion of an HTML string, with Javascript?

UPDATE: I am no longer specifically in need of the answer to this question - I was able to solve the (larger) problem I had in an entirely different way (see my comment). However, I'll check in occasionally, and if a viable answer arrives, I'll accept it. (It may take a week or three, though, as I'm only here sporadically.)
I have a string. It may or may not have HTML tags in it. So, it could be:
'This is my unspanned string'
or it could be:
'<span class="someclass">This is my spanned string</span>'
or:
'<span class="no-text"></span><span class="some-class"><span class="other-class">This is my spanned string</span></span>'
or:
'<span class="no-text"><span class="silly-example"></span></span><span class="some-class">This is my spanned string</span>'
I want to find the index of a substring, but only in the portion of the string that, if the string were turned into a DOM element, would be (a) TEXT node(s). In the example, only in the part of the string that has the plain text This is my string.
However, I need the location of the substring in the whole string, not only in the plain text portion.
So, if I'm searching for "span" in each of the strings above:
searching the first one will return 13 (0-based),
searching the second will skip the opening span tag in the string and return 35 for the string span in the word spanned
searching the third will skip the empty span tag and the openings of the two nested span tags, and return 91
searching the fourth will skip the nested span tags and the opening of the second span tag, and return 100
I don't want to remove any of the HTML tags, I just don't want them included in the search.
I'm aware that attempting to use regex is almost certainly a bad idea, probably even for simplistic strings as my code will be encountering, so please refrain from suggesting it.
I'm guessing I will need to use an HTML parser (something I've never done before). Is there one with which I can access the original parsed strings (or at least their lengths) for each node?
Might there be a simpler solution than that?
I did search around and wasn't been able to find anyone ask this particular question before, so if someone knows of something I missed, I apologize for faulty search skills.

The search could loop through the string char by char. If inside a tag, skip the tag, search the string only outside tags and remember partial match in case the text is matched partially then interrupted with another tag, continue the search outside the tag.

Here is a little function I came up with:
function customSearch(haysack,needle){
var start = 0;
var a = haysack.indexOf(needle,start);
var b = haysack.indexOf('<',start);
while(b < a && b != -1){
start = haysack.indexOf('>',b) + 1;
a = haysack.indexOf(needle,start);
b = haysack.indexOf('<',start);
}
return a;
}
It returns the results you expected based in your examples. Here is a JSFiddle where the results are logged in the console.

Let's start with your third example:
var desiredSubString = 'span';
var entireString = '<span class="no-text"></span><span class="some-class"><span class="other-class">This is my spanned string</span></span>';
Remove all HTML elements from entireString, above, to establish textString:
var textString = entireString.replace(/(data-([^"]+"[^"]+")/ig,"");
textString = textString.replace(/(<([^>]+)>)/ig,"");
You can then find the index of the start of the textString within the entireString:
var indexOfTextString = entireString.indexOf(textString);
Then you can find the index of the start of the substring you're looking for within the textString:
var indexOfSubStringWithinTextString = textString.indexOf(desiredSubString);
Finally you can add indexOfTextString and indexOfSubStringWithinTextString together:
var indexOfSubString = indexOfTextString + indexOfSubStringWithinTextString;
Putting it all together:
var entireString = '<span class="no-text"></span><span class="some-class"><span class="other-class">This is my spanned string</span></span>';
var desiredSubString = 'span';
var textString = entireString.replace(/(data-([^"]+"[^"]+")/ig,"");
textString = textString.replace(/(<([^>]+)>)/ig,"");
var indexOfTextString = entireString.indexOf(textString);
var indexOfSubStringWithinTextString = textString.indexOf(desiredSubString);
var indexOfSubString = indexOfTextString + indexOfSubStringWithinTextString;

You could use the browser's own HTML parser and XPath engine to search only inside the text nodes and do whatever processing you need.
Here's a partial solution:
var haystack = ' <span class="no-text"></span><span class="some-class"><span class="other-class">This is my spanned string</span></span>';
var needle = 'span';
var elt = document.createElement('elt');
elt.innerHTML = haystack;
var iter = document.evaluate('.//text()[contains(., "' + needle + '")]', elt).iterateNext();
if (iter) {
var position = iter.textContent.indexOf(needle);
var range = document.createRange();
range.setStart(iter, position);
range.setEnd(iter, position + needle.length);
// At this point, range points at the first occurence of `needle`
// in `haystack`. You can now delete it, replace it with something
// else, and so on, and after that, set your original string to the
// innerHTML of the document fragment representing the range.
console.log(range);
}
JSFiddle.

How to delete an item from a serialized list?

I make a serialized list (with JQuery) and then want to delete a Parameter/Value pair from the list. What's the best way to do this? My code seems kinda clunky to take care of edge conditions that the Parameter/Value pair might be first, last, or in the middle of the list.
function serializeDeleteItem(strSerialize, strParamName)
{
// Delete Parameter/Value pair from Serialized list
var strRegEx;
var rExp;
strRegEx = "((^[?&]?" + strParamName + "\=[^\&]*[&]?))|([&]" + strParamName + "\=[^\&]*)|(" + strParamName + "\=[^\&]*[&])";
rExp = new RegExp(strRegEx, "i");
strSerialize = strSerialize.replace(rExp, "");
return strSerialize;
}
Examples / Test rig at http://jsfiddle.net/7Awzw/
EDIT: Modified the test rig to preserve any leading "?" or "&" so that function could be used with URL Query String or fragment of serialized string
See: http://jsfiddle.net/7Awzw/5/

This version is longer than yours, but imho it's more maintainable. It will find and remove the serialized parameter regardless of where it is in the list.
Notes:
To avoid problems with removing items in the middle of an array, we iterate in reverse.
For exact matching of parameter names, we expect them to start at the beginning of the split string, and to terminate with =.
Assuming there is just one instance of the given param, we break once it's found. If there may be more, just remove that line.
Code
function serializeDeleteItem(strSerialize, strParamName)
{
var arrSerialize = strSerialize.split("&");
var i = arrSerialize.length;
while (i--) {
if (arrSerialize[i].indexOf(strParamName+"=") == 0) {
arrSerialize.splice(i,1);
break; // Found the one and only, we're outta here.
}
}
return arrSerialize.join("&");
}
This fails a few of your tests - the ones with serialized strings starting with '?' or '&'. If you feel those are valid, then you could do this at the start of the function, and all tests will pass:
if (strSerialize.length && (strSerialize[0] == '?' || strSerialize[0] == '&'))
strSerialize = strSerialize.slice(1);
Performance Comparison
I've put together a test in jsperf to compare the regex approach with this string method. It's reporting that the regex solution is 49% slower than strings, in IE10 on 32-bit Win7.

Apparent trouble with behavior of substring in JavaScript

I am writing a recursive algorithm to build a finite state automaton by parsing a regular expression. The automaton iterates through the expression, pushing characters to a stack and operators to an "operator stack." When I encounter "(" (indicating a grouping operation), I push a "sub automaton" to the stack and pass the rest of the pattern to the sub automaton to parse. When that automaton encounters ")", it passes the rest of the string up to the parent automaton to finish parsing. Here is the code:
var NFA = function(par) {
this.stack = [];
this.op_stack = [];
this.parent = par;
};
NFA.prototype.parse = function(pattern) {
var done = false;
for(var i in pattern) {
if (done === true) {
break;
}
switch(pattern.charAt(i)) {
case "(":
var sub_nfa = new NFA(this);
this.stack.push(sub_nfa);
sub_nfa.parse(pattern.substring(i+1, pattern.length));
done = true;
break;
case ")":
if (this.parent !== null) {
var len = pattern.length;
/*TROUBLE SPOT*/
this.parent.parse(pattern.substring(i, pattern.length));
done = true;
break;
}
case "*":
this.op_stack.push(operator.KLEENE);
break;
case "|":
this.op_stack.push(operator.UNION);
break;
default:
if(this.stack.length > 0) {
//only push concat after we see at least one symbol
this.op_stack.push(operator.CONCAT);
}
this.stack.push(pattern.charAt(i));
}
}
};
Note the area marked "TROUBLE SPOT". Given the regular expression "(a|b)a", the call this.parent.parse, is called exactly once: when the sub-automaton encounters ")". At this point, pattern.substring(i, pattern.length) = ")a". This "works", but it isn't correct because I need to consume the ")" input before I pass the string to the parent automaton. However, if I change the call to this.parent.parse(pattern.substring(i+1, pattern.length), parse gets handed the empty string! I have tried stepping through the code and I cannot explain this behavior. What am I missing?
At Juan's suggestion, I made a quick jsfiddle to show the problem when trying to parse "(a|b)a" with this algorithm. In the ")" case, it populates an empty div with the substring at the i index and the substring at the i+1 index. It shows that while there are 2 characters in the substring at i, the substring at i+1 is the empty string! Here's the link: http://jsfiddle.net/XC6QM/1/
EDIT: I edited this question to reflect the fact that using charAt(i) doesn't change the behavior of the algorithm.

I think the previous answer was on the right track. But there also looks to me to be an off-by-one error. Shouldn't you be increasing the index for your substring? You don't want to include the ")" in the parent parse, right?
this.parent.parse(pattern.substring(i + 1, pattern.length));
But this will still fail because of the error Juan mentioned. A quick temporary fix to test this would be to convert the i to a number:
this.parent.parse(pattern.substring(+i + 1, pattern.length));
This might do it for you. But you should probably go back and switch away from the for-in loop on the string. I think that's causing your issue. Turn it into an array with str.split('') and then use an integer to loop. That will prevent further such issues.

The real problem is the fact that you were using a for in to iterate through the characters of the string. With the for in loop, your i is going to be a string, therefore, when you try to do i+1, it does string concatenation.
If you change your iteration to be
for(var i=0; i < pattern.length; i++) {
Then it all works fine http://jsfiddle.net/XC6QM/2/
Scott's answer correctly identified the problem but I think his solution (converting the indexes to numbers) is not ideal. You're better off looping with a numeric index to begin with
Also, you should not use brackets to access characters within a string, that does not work in IE 7
switch(pattern[i]) {
should be
switch(pattern.charAt(i)) {

How to search DOM to count the number of $ symbol found on a product page?

I am looking to find the best possible way to find how many $ symbols are on a page. Is there a better method than reading document.body.innerHTML and calc how many $-as are on that?

Your question can be split into two parts:
How can we get the the webpage text content without HTML tags?
We can generalize the second question a bit.
How can we find the number of string occurrences in another string?
And the 'best possible way to do this':
Amaan got the idea right of finding the text, but lets take it further.
var text = document.body.innerText || document.body.textContent;
Adding textContent to the code helps us cover more browsers, since innerText is not supported by all of them.
The second part is a bit trickier. It all depends on the number of '$' symbol occurrences on the page.
For example, if we know for sure, that there is at least one occurrence of the symbol on the page we would use this code:
text.match(/\$/g).length;
Which performs a global regular expression match on the given string and counts the length of the returned array. It's pretty fast and concise.
On the other hand, if we're not sure if the symbol appears on the page at least once, we should modify the code to look like this:
if (match = text.match(/\$/g)) {
match.length;
}
This just checks the value returned by the match function and if it's null, does nothing.
I would recommend using the third option only when there is a large occurrence of the symbols in the page or you're going to perform the search many many times. This is a custom function (taken from here) to count the occurrence of the specified string in another string. It performs better than the other two, but is longer and harder to understand.
var occurrences = function(string, subString, allowOverlapping) {
string += "";
subString += "";
if (subString.length <= 0) return string.length + 1;
var n = 0,
pos = 0;
var step = (allowOverlapping) ? (1) : (subString.length);
while (true) {
pos = string.indexOf(subString, pos);
if (pos >= 0) {
n++;
pos += step;
} else break;
}
return (n);
};
occurrences(text, '$');
I'm also including a little jsfiddle 'benchmark' so you can compare these three different approaches yourself.
Also: No, there isn't a better way of doing this than just getting the body text and counting how many '$' symbols there are.

You should probably use document.body.innerText or document.body.textContent to avoid getting your HTML give you false positives.
Something like this should work:
document.body.innerText.match(/\$/g).length;
An alternate way I can think of, would be to use window.find like this:
var len = 0;
while(window.find('$') === true){
len++;
}
(This may be unreliable because it depends on where the user clicked last. It will work fine if you do it onload, before any user interaction.)