Remove CSS class from element with JavaScript (no

Question

This question already has an answer here:

• How to change an element's class with JavaScript? 25 answers

Could anyone let me know how to remove a class on an element using JavaScript only? Please do not give me an answer with jQuery as I can't use it, and I don't know anything about it.

Answer 1

var element = document.getElementById('example_id');
var remove_class = 'example_class';

element.className = element.className.replace(' ' + remove_class, '').replace(remove_class, '');

Answer 2

Edit

Okay, complete re-write. It's been a while, I've learned a bit and the comments have helped.

Node.prototype.hasClass = function (className) {
    if (this.classList) {
        return this.classList.contains(className);
    } else {
        return (-1 < this.className.indexOf(className));
    }
};

Node.prototype.addClass = function (className) {
    if (this.classList) {
        this.classList.add(className);
    } else if (!this.hasClass(className)) {
        var classes = this.className.split(" ");
        classes.push(className);
        this.className = classes.join(" ");
    }
    return this;
};

Node.prototype.removeClass = function (className) {
    if (this.classList) {
        this.classList.remove(className);
    } else {
        var classes = this.className.split(" ");
        classes.splice(classes.indexOf(className), 1);
        this.className = classes.join(" ");
    }
    return this;
};

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Old Post

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I was just working with something like this. Here's a solution I came up with...

// Some browsers don't have a native trim() function
if(!String.prototype.trim) {
    Object.defineProperty(String.prototype,'trim', {
        value: function() {
            return this.replace(/^\s+|\s+$/g,'');
        },
        writable:false,
        enumerable:false,
        configurable:false
    });
}
// addClass()
// first checks if the class name already exists, if not, it adds the class.
Object.defineProperty(Node.prototype,'addClass', {
    value: function(c) {
        if(this.className.indexOf(c)<0) {
            this.className=this.className+=' '+c;
        }
        return this;
    },
    writable:false,
    enumerable:false,
    configurable:false
});
// removeClass()
// removes the class and cleans up the className value by changing double 
// spacing to single spacing and trimming any leading or trailing spaces
Object.defineProperty(Node.prototype,'removeClass', {
    value: function(c) {
        this.className=this.className.replace(c,'').replace('  ',' ').trim();
        return this;
    },
    writable:false,
    enumerable:false,
    configurable:false
});

Now you can call myElement.removeClass('myClass')

or chain it: myElement.removeClass("oldClass").addClass("newClass");

Answer 3

document.getElementById("MyID").className =
    document.getElementById("MyID").className.replace(/\bMyClass\b/,'');

where MyID is the ID of the element and MyClass is the name of the class you wish to remove.

---

UPDATE: To support class names containing dash character, such as "My-Class", use

document.getElementById("MyID").className =
  document.getElementById("MyID").className
    .replace(new RegExp('(?:^|\\s)'+ 'My-Class' + '(?:\\s|$)'), ' ');

Answer 4

All of these answers are way too complicated, try

var string = "Hello, whats on your mind?";
var new_string = string.replace(', whats on your mind?', '');

The result would be a return of the string

Hello

Super easy. Credits go to jondavidjohn Remove portion of string in Javascript

Answer 5

try:

function removeClassName(elem, name){
    var remClass = elem.className;
    var re = new RegExp('(^| )' + name + '( |$)');
    remClass = remClass.replace(re, '$1');
    remClass = remClass.replace(/ $/, '');
    elem.className = remClass;
}

Answer 6

It's very simple, I think.

document.getElementById("whatever").classList.remove("className");