How can call javascript function without button click in html?

I'd suggest you to use addEvent,removeEvent function approaches due to cross browser issues.

addEvent function is capable of to add events on elements, while removeEvent remove them

if [ document.addEventListener ] { // if addEventListener provided
    this.addEvent = function[elem, type, fn] {
        elem.addEventListener[type, fn, false];
        return fn;
    };

    this.removeEvent = function[elem, type, fn] {
        elem.removeEventListener[type, fn, false];
    };
} else if [ document.attachEvent ] { // if attachEvent provided
    this.addEvent = function[elem, type, fn] {
        var bound = function[] {
            return fn.apply[elem, arguments];
        };
        elem.attachEvent["on" + type, bound];
        return bound;
    };

    this.removeEvent = function [elem, type, fn] {
        elem.detachEvent["on" + type, fn];
    };
}

For example if you have HTML

JavaScript

addEvent[document.getElementById["source"],"keydown",function[]{ // event will occur on keyup
    document.getElementById["result"].innerHTML = this.value; // this refers to textarea element
}];

JSFiddle

PS. Check out attachEvent and addEventListener methods

My function is a timer that should run when the page is displayed. I wrote

    startcountdown[];

In html but this doesn't work. How can I call that function? I don't need special event to happen before calling it.

asked May 3, 2016 at 11:05

Sargsyan GrigorSargsyan Grigor

4911 gold badge4 silver badges19 bronze badges

10

window.onload = function[] {
   startcountdown[];
}
 

answered May 3, 2016 at 11:11

overburnoverburn

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You may use JavaScripts native window.onload function, if you are not using any other library like jQuery or something else.

  window.onload = function[] {
    startcountdown[];
  };

I'd also like to mention that you could also start a function by just adding it to the end of your markup. That being said, if you define a function function startcountdown[] { } at the very beginning of your html, you could simply use startcountdown[]; at the very end of your html [e.g. before your closing tag].

This approach would simply execute your function after your DOM has being loaded, since it's defined as the last call of your markup.

answered May 3, 2016 at 11:11

Aer0Aer0

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you can put it into tag using 'onload' event:

or just use jQuery:

$[document].ready[function[] {
    yourFunct[];
}];

answered May 3, 2016 at 11:19

Pardeep PathaniaPardeep Pathania

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you can try this put onload="startcountdown[];" in html body tag

answered May 3, 2016 at 11:28

By calling your function in page on-load

window.onload = startcountdown;
 function startcountdown[]{
   //write your code here
}
 

answered May 3, 2016 at 11:20

nisarnisar

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