In-depth understanding of the loop statement for statement in javascript_javascript skills

Loop statements are often used in program implementation, among which the for loop is found in most languages. In JavaScript, there are several different uses of for loops. Here are my understandings of each.

First type: (usually, loop to perform related operations)

Copy code The code is as follows:

var objA=document.getElementsByTagName("a");
var i,max;
for(i=0,max=objA.length;iobjA[i].onclick=function(){
alert(this.innerHTML);
}

}

loop, registering hyperlink tags in turn Click operation

The second type: (for objects, operating object content)

Copy code The code is as follows :

var person={name:'wmhello',age:'28'};
var tips=''; for(var obj in person){
tips =obj '-->' person[obj] 'n'

}

alert(tips)

The third type: (commonly used for arrays, for arrays Perform specific operations)

Copy code The code is as follows:

var num=[1,3 ,5];
var total=0;
num.forEach(function(e){
total =e;
});
alert(total);

This forEach loop works in firefox and chrome