javascript-初级-day07

day01-运算符

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>

<script>
/*
var i = 0;
i++;
if( i === 5 ){
    i = 0;
}
i%=5;
*/
window.onload = function (){
    var aLi = document.getElementsByTagName('li');
    var arr = [ 'red', 'yellow', 'blue' ];
    
    for( var i=0; i<aLi.length; i++ ){
        
        aLi[i].index = i;
        
        aLi[i].style.background = arr[i%arr.length];
        
        aLi[i].onmouseover = function (){
            this.style.background = 'gray';
        };
        aLi[i].onmouseout = function (){
            this.style.background = arr[this.index%arr.length];
        };
    }
};
</script>
<style>
li { height:24px; margin-bottom:3px; list-style:none; }
</style>
</head>

<body>

<ul id="ul1">
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
</ul>

</body>
</html>

移入哪一行哪一行变灰色

反选

<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
<script>
window.onload = function (){
    var aInp = document.getElementsByTagName('input');
    
    // aInp[1].checked = false;
    // aInp[2].checked = true;
    
    aInp[0].onclick = function (){
        for( var i=1; i<aInp.length; i++ ){
            aInp[i].checked = !aInp[i].checked;
            /*
            if( aInp[i].checked ) {
                aInp[i].checked = false;
            } else {
                aInp[i].checked = true;
            }
            */
        }
    };
};
</script>
</head>

<body>

<input type="button" value="反选" />
<ul>
    <li><input type="checkbox" checked /></li>
    <li><input type="checkbox" /></li>
    <li><input type="checkbox" checked /></li>
    <li><input type="checkbox" /></li>
    <li><input type="checkbox" /></li>
</ul>

</body>
</html>

 

posted @ 2019-02-25 14:19  三号小玩家  阅读(111)  评论(0)  编辑  收藏  举报
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