Develop Reference

How to extract query string parameters from URL in JavaScript

I have a URL
https://www.yellowpages.com/search?search_terms=Generator+Repair&geo_location_terms=Adamsville%2C+Alabama
I want to get search_terms (Generator+Repair) and geo_location_terms (Adamsville%2C+Alabama)
How I can do this?

The easiest and most idiomatic way to do this in JavaScript is using the URL class:
const url = new URL('https://www.yellowpages.com/search?search_terms=Generator+Repair&geo_location_terms=Adamsville%2C+Alabama')
console.log(url.searchParams.get('search_terms'));
console.log(url.searchParams.get('geo_location_terms'));
MDN reference here.

You can use the following Javascript code to store the GET parameters into an object:
<script>
var URL = "https://www.yellowpages.com/search?search_terms=Generator+Repair&geo_location_terms=Adamsville%2C+Alabama";
var result = {};
URL.substring(URL.indexOf("?") + 1).split('&').forEach(function(x){
var arr = x.split('=');
arr[1] && (result[arr[0]] = arr[1]);
});
console.log(result.search_terms);
//OUTPUT: "Generator+Repair"
console.log(result.geo_location_terms);
//OUTPUT: "Adamsville%2C+Alabama"
</script>

You can use the following regex to get the 2 values:
/search_terms=(.*)&geo_location_terms=(.*)/
This is a very basic regex, that starts by matching 'search_terms=' then creates a Group that matches any number of any char up to the '&' sign, then matches 'geo_location_terms=' and finally creates a Group that matches any number of any char.
Your desired output will be in Group 1 and Group 2.
How to use:
var url = 'https://www.yellowpages.com/search?search_terms=Generator+Repair&geo_location_terms=Adamsville%2C+Alabama';
var regex = /search_terms=(.*)&geo_location_terms=(.*)/;
var match = url.match(regex);
var search_terms = match[1];
var geo_location_terms = match[2];

Remove string between two variables

I have a string which has some data with a few special characters, Need to remove the data between the desired special char in JavaScript.
The special char would be obtained in a variable.
var desiredChar = "~0~";
And Imagine this to be the Input string:
~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~
So I'm supposed to remove the text in bold.
The desired output is supposed to be-
~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~
I've tried using "Replace" and "Regex", but as the desired character is being passed in a variable and keeps changing I'm facing difficulties.

You can create your own regex based on whatever the bounding character(s) are that contain the text you want removed, and then replace any text that matches that regex with a blank string "".
The JS below should work for your use case (and it should work for multiple occurrences as well):
var originalText = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
var desiredChar = "~0~";
var customRegex = new RegExp(desiredChar + ".*?" + desiredChar, "gi");
var processedText = originalText.replace(customRegex, "");
console.log(processedText);

You can build your regex from the constructor with a string input.
var desiredChar = "~0~";
// use the g flag in your regex if you want to remove all substrings between desiredChar
var myRegex = new Regex(desiredChar + ".*" + desiredChar, 'ig');
var testString = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
testString = testString.replace(myRegex, "");

Given input string you can use .indexOf(), .lastIndexOf() and .slice().
Note, OR character | passed to RegExp constructor should be escaped to avoid RegExp created by passing string interpreting | character as OR | within resulting RegExp passed to .replace().
var desiredChar = "~0~";
var str = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
var not = str.slice(str.indexOf(desiredChar), str.lastIndexOf(desiredChar) + desiredChar.length);
// escape OR `|`
var res = str.replace(new RegExp(not.replace(/[|]/g, "\\|")), "");
console.log(res)

You can use the RegExp object:
var regexstring = "whatever";
var regexp = new RegExp(regexstring, "gi");
var str = "whateverTest";
var str2 = str.replace(regexp, "other");
document.write(str2);
Then you can construct regexstring in any way you want.
You can read more about it at http://www.regular-expressions.info/javascript.html

Split the date! (It's a string actually)

I want to split this kind of String :
"14:30 - 19:30" or "14:30-19:30"
inside a javascript array like ["14:30", "19:30"]
so I have my variable
var stringa = "14:30 - 19:30";
var stringes = [];
Should i do it with regular expressions? I think I need an help

You can just use str.split :
var stringa = "14:30 - 19:30";
var res = str.split("-");

If you know that the only '-' present will be the delimiter, you can start by splitting on that:
let parts = input.split('-');
If you need to get rid of whitespace surrounding that, you should trim each part:
parts = parts.map(function (it) { return it.trim(); });
To validate those parts, you can use a regex:
parts = parts.filter(function (it) { return /^\d\d:\d\d$/.test(it); });
Combined:
var input = "14:30 - 19:30";
var parts = input.split('-').map(function(it) {
return it.trim();
}).filter(function(it) {
return /^\d\d:\d\d$/.test(it);
});
document.getElementById('results').textContent = JSON.stringify(parts);
<pre id="results"></pre>

Try this :
var stringa = "14:30 - 19:30";
var stringes = stringa.split("-"); // string is "14:30-19:30" this style
or
var stringes = stringa.split(" - "); // if string is "14:30 - 19:30"; style so it includes the spaces also around '-' character.
The split function breaks the strings in sub-strings based on the location of the substring you enter inside it "-"
. the first one splits it based on location of "-" and second one includes the spaces also " - ".
*also it looks more like 24 hour clock time format than data as you mentioned in your question.

var stringa = '14:30 - 19:30';
var stringes = stringa.split("-");

.split is probably the best way to go, though you will want to prep the string first. I would go with str.replace(/\s*-\s*/g, '-').split('-'). to demonstrate:
var str = "14:30 - 19:30"
var str2 = "14:30-19:30"
console.log(str.replace(/\s*-\s*/g, '-').split('-')) //outputs ["14:30", "19:30"]
console.log(str2 .replace(/\s*-\s*/g, '-').split('-')) //outputs ["14:30", "19:30"]

Don't forget that you can pass a RegExp into str.split
'14:30 - 19:30'.split(/\s*-\s*/); // ["14:30", "19:30"]
'14:30-19:30'.split(/\s*-\s*/); // ["14:30", "19:30"]

Passing Parameter into function match

I am using the function match for a search engine, so whenever a user types a search-string I take that string and use the match function on an array containing country names, but it doesn't seem to work.
For example if I do :
var string = "algeria";
var res = string.match(/alge/g); //alge is what the user would have typed in the search bar
alert(res);
I get a string res = "alge": //thus verifying that alge exists in algeria
But if I do this, it returns null, why? and how can I make it work?
var regex = "/alge/g";
var string = "algeria";
var res = string.match(regex);
alert(res);

To make a regex from a string, you need to create a RegExp object:
var regex = new RegExp("alge", "g");
(Beware that unless your users will be typing actual regular expressions, you'll need to escape any characters that have special meaning within regular expressions - see Is there a RegExp.escape function in Javascript? for ways to do this.)

You don't need quotes around the regex:
var regex = /alge/g;

Remove the quotes around the regex.
var regex = /alge/g;
var string = "algeria";
var res = string.match(regex);
alert(res);

found the answer, the match function takes a regex object so have to do
var regex = new RegExp(string, "g");
var res = text.match(regex);
This works fine

Cannot extract parts of a string

I have a string like this : SPList:6E5F5E0D-0CA4-426C-A523-134BA33369D7?SPWeb:C5DD2ADA-E0C4-4971-961F-233789297FE9:.
Using Javascript, I would like to extract the two IDs (which can be different) : 6E5F5E0D-0CA4-426C-A523-134BA33369D7 and C5DD2ADA-E0C4-4971-961F-233789297FE9.
I'm using this regular expression : ^SPList\:(?:[0-9A-Za-z\-]+)\?SPWeb\:(?:[0-9A-Za-z\-]+)\:$.
I expect this expression to extract into two matching groups the two IDs.
By now, my code is :
var input = "SPList:6E5F5E0D-0CA4-426C-A523-134BA33369D7?SPWeb:C5DD2ADA-E0C4-4971-961F-233789297FE9:";
var myregex = /^SPList\:(?:[0-9A-Za-z\-]+)\?SPWeb\:(?:[0-9A-Za-z\-]+)\:$/g;
var match = input.match(myregex);
var listId = match[0];
var webId = match[1];
However, this is not working as expected. The first match contains the whole string, and the second match is undefined.
What is the proper way to extract my ID's?
Here is a jsfiddle that illustrate my issue.

This should suit your needs:
var regex = /^SPList:([0-9A-F-]+)[?]SPWeb:([0-9A-F-]+):$/g;
var match = regex.exec(input);
var listId = match[1];
var webId = match[2];
I simply replaced the non-capturing groups of your initial regex by capturing groups, and used regex.exec(input) instead of input.match(regex) to get the captured data. Also, since the IDs seem to be hexadecimal values, I used A-F instead of A-Z.

try this:
var myregex = /[^\:]([0-9A-Z\-]+)[^\?|\:]/g;
var match = input.match(myregex);
alert("listID: " + match[1] + "\n" + "webID: " + match[3]);