Develop Reference

Javascript extract string from start to 0/, removing anything after 0/

I have a string which looks like this:
file:///storage/emulated/0/Pictures/IMG212.jpg
I want to remove anything from Pictures onwards so I would get this:
file:///storage/emulated/0/
How can I do this?

var regex = /^.*0\//
var matches = str.match(regex);
console.log(matches[0]);

You could find the index of /0 and use substring to select everything up to that point, like so:
const line = "file:///storage/emulated/0/Pictures/IMG212.jpg";
// Get the location of "/0", will be 24 in this example
const endIndex = line.indexOf("/0");
// Select everything from the start to the endIndex + 2
const result = line.substring(0, endIndex+2);
The reason why we add +2 to the endIndex is because the string that we're trying to find is 2 characters long:
file:///storage/emulated/0/Pictures/IMG212.jpg
[24]--^^--[25]

You can split the string using split method:
const myString = "file:///storage/emulated/0/Pictures/IMG212.jpg";
const result = myString.split("0/")[0] + "0/";
console.log(result); // file:///storage/emulated/0/
documentation for split method on MDN

How to get a sub-string after the last specified char ? Javascript

lets say I have the following string :
var text = "A_B_C_190"
I want to be able to extract the number at the end (the last 3 chars after the last _ )
I tired :
text.substr(text.indexOf('_'), -1)
but that gave me null

You can use string.prototype.split and array.prototype.pop:
var text = "A_B_C_190";
console.log(text.split('_').pop());

You have to use lastIndexOf method.
var text = "A_B_C_190"
ans = text.substr(text.lastIndexOf('_')+1)
console.log(ans)
If you want to convert it to an integer, use parseInt(ans)

Split text with a single code

var objname = "Image1-123456-789.png"
quick question i wanted to split this text without match them together again.
here is my code
var typename = objname.split("-");
//so it will be Image1,123456,789.png
var SplitNumber = typename[1]+'-'+typename[2];
var fullNumber = SplitCode.split('.')[0];
to get what i wanted
my intention is to get number is there anyway i can split them without join them and split again ?
can a single code do that perfectly ? my code look like so many job.
i need to get the 123456-789.

The String.prototype.substring() method extracts the characters from a string, between two specified indices, and returns the new sub string.
This method extracts the characters in a string between "start" and "end", not including "end" itself.
var objname = "Image1-123456-789.png";
var newname = objname.substring(objname.indexOf("-")+1, objname.indexOf("."));
alert(newname);

An alternate can be using Join. You can use slice to fetch range of values in array and then join them using -.
var objname = "Image1-123456-789.png";
var fullnumber = objname.split("-").slice(1).join("-").split(".")[0];
alert(fullnumber)
Reference
Join Array from startIndex to endIndex

Here is your solution
var objname = "Image1-123456-789.png";
var typename= objname.split("-");
var again=typename[2];
var again_sep= again.split(".");
var fullNumber =typename[1]+'-'+again_sep[0];

Trim a variable's value until it reaches to a certain character

so my idea is like this..
var songList = ["1. somesong.mid","13. abcdef.mid","153. acde.mid"];
var newString = myString.substr(4); // i want this to dynamically trim the numbers till it has reached the .
// but i wanted the 1. 13. 153. and so on removed.
// i have more value's in my array with different 'numbers' in the beginning
so im having trouble with this can anyone help me find a more simple solution which dynamically chop's down the first character's till the '.' ?

You can do something like
var songList = ["1. somesong.mid","13. abcdef.mid","153. acde.mid"];
songList.forEach(function(value, i){
songList[i] = value.replace(/\d+\./, ''); //value.substr(value.indexOf('.') + 1)
});
Demo: Fiddle

You can use the string .match() method to extract the part up to and including the first . as follows:
var newString = myString.match(/[^.]*./)[0];
That assumes that there will be a match. If you need to allow for no match occurring then perhaps:
var newString = (myString.match(/[^.]*./) || [myString])[0];
If you're saying you want to remove the numbers and keep the rest of the string, then a simple .replace() will do it:
var newString = myString.replace(/^[^.]*. */, "");

Javascript split to split string in 2 parts irrespective of number of spit characters present in string

I want to split a string in Javascript using split function into 2 parts.
For Example i have string:
str='123&345&678&910'
If i use the javascripts split, it split it into 4 parts.
But i need it to be in 2 parts only considering the first '&' which it encounters.
As we have in Perl split, if i use like:
($fir, $sec) = split(/&/,str,2)
it split's str into 2 parts, but javascript only gives me:
str.split(/&/, 2);
fir=123
sec=345
i want sec to be:
sec=345&678&910
How can i do it in Javascript.

var subStr = string.substring(string.indexOf('&') + 1);
View this similar question for other answers:
split string only on first instance of specified character

You can use match instead of split:
str='123&345&678&910';
splited = str.match(/^([^&]*?)&(.*)$/);
splited.shift();
console.log(splited);
output:
["123", "345&678&910"]

You can remain on the split part by using the following trick:
var str='123&345&678&910',
splitted = str.split( '&' ),
// shift() removes the first item and returns it
first = splitted.shift();
console.log( first ); // "123"
console.log( splitted.join( '&' ) ); // "345&678&910"

I wrote this function:
function splitter(mystring, mysplitter) {
var myreturn = [],
myindexplusone = mystring.indexOf(mysplitter) + 1;
if (myindexplusone) {
myreturn[0] = mystring.split(mysplitter, 1)[0];
myreturn[1] = mystring.substring(myindexplusone);
}
return myreturn;
}
var str = splitter("hello-world-this-is-a-test", "-");
console.log(str.join("<br>"));
//hello
//world-this-is-a-test​​​
The output will be either an empty array (not match) or an array with 2 elements (before the split and everything after)
Demo

I have that:
var str='123&345&678&910';
str.split('&',1).concat( str.split('&').slice(1).join('&') );
//["123", "345&678&910"]
str.split('&',2).concat( str.split('&').slice(2).join('&') );
//["123", "345", "678&910"];
for convenience:
String.prototype.mySplit = function( sep, chunks) {
chunks = chunks|=0 &&chunks>0?chunks-1:0;
return this.split( sep, chunks )
.concat(
chunks?this.split( sep ).slice( chunks ).join( sep ):[]
);
}

What about the use of split() and replace()?:
Given we have that string str='123&345&678&910' We can do
var first = str.split("&",1); //gets the first word
var second = str.replace(first[0]+"&", ""); //removes the first word and the ampersand
Please note that split() returns an array that is why getting the index with first[0] is recommended, however, without getting the index, it still worked as needed i.e first+"&".
Feel free to replace the "&" with the string you need to split with.
Hope this helps :)