JSFiddle - React, Tailwind, and code Playground

JavaScript

function fn1( value ){
    console.log( value );
}

function fn2( value ){
    fn1("fn2 says:" + value);
    return false;
}

var callbacks = $.Callbacks( "once" );
callbacks.add( fn1 );
callbacks.fire( "foo" );
callbacks.add( fn2 );
callbacks.add( fn1 );
callbacks.fire( "bar" );
callbacks.remove( fn2 );
callbacks.fire( "foobar" );
console.log(callbacks.disabled());