JS (bind events)

Event Binding Method 1: Binding in Properties

<input type="button" value="+" onclick="fun1()">
<script>
    function fun1(){
        alert(123);
    }
</script>

The event binding method has a parameter this, this refers to this tag

<div class="div1" onclick="fun1(this)">div1</div>
<script>
    function fun1(e){
        alert(e.innerHTML);
    }
</script>

 

Event binding method 2: Binding in the script tag

<div class="div1">div1</div>
<script>
    var tmp=document.getElementsByClassName("div1")[0];
    tmp.onclick = function (){                  // onclick is not followed by parentheses 
        alert( 123 );
    }
</script>

 

Event binding method two this

<div class="div1">div1</div>
<script>
    var tmp=document.getElementsByClassName("div1")[0];
    tmp.onclick=function(){
        alert( this .innerHTML);               // this also refers to the tag 
    }
 </ script >