Trim String in JavaScript

Trim string in JavaScript

All browsers since IE9+ have trim() method for strings:

" \n test \n ".trim(); // returns "test" here

For those browsers who does not support trim(), you can use this polyfill from MDN:

if (!String.prototype.trim) {
    (function() {
        // Make sure we trim BOM and NBSP
        var rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g;
        String.prototype.trim = function() {
            return this.replace(rtrim, '');
        };
    })();
}

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That said, if using jQuery, $.trim(str) is also available and handles undefined/null.

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See this:

String.prototype.trim=function(){return this.replace(/^\s+|\s+$/g, '');};

String.prototype.ltrim=function(){return this.replace(/^\s+/,'');};

String.prototype.rtrim=function(){return this.replace(/\s+$/,'');};

String.prototype.fulltrim=function(){return this.replace(/(?:(?:^|\n)\s+|\s+(?:$|\n))/g,'').replace(/\s+/g,' ');};

Trim specific character from a string

One line is enough:

var x = '|f|oo||';
var y = x.replace(/^\|+|\|+$/g, '');
document.write(x + '<br />' + y);

How can i trim this javascript string?

Is it always a pound symbol? Just replace it.

val = val.replace('£', ''); // then trim

Javascript - Apply trim function to each string in an array

String.prototype.trim.apply is the Function.prototype.apply method without being bound to trim. map will invoke it with the string, the index and the array as arguments and nothing (undefined) for the thisArg - however, apply expects to be called on functions:

var apply = String.prototype.trim.apply;
apply.call(undefined, x[0], 0, x) // TypeError

What you can do is passing the trim function as the context for call:

[' aa ', ' bb '].map(Function.prototype.call, String.prototype.trim)
// ['aa', 'bb']

What happens here is

var call = Function.prototype.call,
    trim = String.prototype.trim;
call.call(trim, x[0], 0, x) ≡
      trim.call(x[0], 0, x) ≡
            x[0].trim(0, x); // the arguments don't matter to trim

trim string from first number in the string in javascript

you can try this,

var title = "IX - Delivery Received 1/15/2018 9:34:00 AM ";

var digit = title.search(/\d/);
var finalname = title.substring(0, digit);

Which outputs "IX - Delivery Received "

How to trim an unwanted continuous string at end in javascript?

Working off Deryck's comments & answer, but allowing for any number of dashes on the end:

const longStr = "Hello ---- TecAdmin------------";

var thing = longStr.replace(/-*$/g, '');

console.log(thing);

Remove all white space from string JavaScript

Use this:

str.replace(/\s+/g, '');

Instead of this:

str.trim()

How can I trim a specific character off the start & end of a string?

You can use RegEx to easily conquer this problem:

myString = myString.replace(/^"+|"+$/g, '');

You can substitute the " with any character (be careful, some characters need to be escaped).

Here's a demo on JSFiddle.

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An explanation of the regular expression:

/ - start RegEx (/)

^"+ - match the start of the line (^) followed by a quote (") 1 or more times (+)

| - or

"+$ - match a quote (") 1 or more times (+) followed by the end of the line ($)

/ - end RegEx (/)

g - "global" match, i.e. replace all

Remove space without using string method trim

Your current solution creates a new string which contains all the non-space characters of the original string, you need to stop looking for spaces as soon as you find a non-space character. Here is an example:

function trimLeftSpace(str) {

    var doneTrimming = false

    var ret = ""

    for (var index = 0; index < str.length; index++) {

        if(str[index] !== ' '){

            doneTrimming = true

        }

        if(doneTrimming){

            ret += str[index]

        }

    }

    return ret;

}

var result = trimLeftSpace("   Angry Bird   ");

console.log("|"+result+"|");

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