javascript - js的for循环改变样式结构-PHP中文网问答

搜索

微信公众号

首页文章专题 AI工具学习编程手册下载最近更新

文章 web3.0 后端开发 web前端数据库开发工具 php框架常见问题科技 Java 系统教程电脑教程硬件教程手机教程软件教程游戏教程自媒体新闻

专题后端开发 web前端数据库开发工具 php框架科技 Java 系统教程电脑教程硬件教程手机教程软件教程游戏教程新闻

AI工具 AI 聊天问答 Agent智能体 AI 文本写作 AI 绘画作图 AI 设计工具 AI 视频创作 AI 音频制作 AI 办公学习 AI 编程开发 Prompt指令

学习大前端后端开发数据库移动端运维开发 UI设计计算机基础

编程手册大前端 JavaScript 后端开发数据库移动端运维开发 UI设计计算机基础 XML Web Services

下载 js特效网站源码工具下载类库下载网站素材学习资源插件扩展手机/移动开发手机游戏

最近更新

javascript - js的for循环改变样式结构

巴扎黑 2017-04-10 16:24:11

[JavaScript讨论组]

408

先放出代码

<!DOCTYPE html>
<html lang="en">
<head>

    <meta charset="UTF-8">
    <title></title>
<script>
    window.onload = function(){
        var body = document.getElementsByTagName('body')[0];
        var btn = body.getElementsByTagName('button');
        for(var num = 0;num < 40;num++){
        body.innerHTML += "<button>" + "按钮" +"</button>";
    }
        for(var num = 0;num < 20;num++){
        //btn[num].style.marginLeft = "15px";
        btn[num].style.position = "absolute";
        btn[num].style.top = num*30 + "px";
        btn[num].style.left = num*30 + "px";
        }

        for(var num = 20;num < 40;num++){
        //btn[num].style.marginLeft = "15px";
        btn[num].style.position = "absolute";
        btn[num].style.top = num*30 + "px";
        btn[num].style.left = num*30 + "px";
        }
    };
</script>

</head>
<body>

</body>
</html>

希望按钮从num=21开始不断上升,然后与之前的按钮形成一个V字

巴扎黑

全部回复(3)

PHPz2017-04-10 16:26:11 3楼

代码如下：

<!DOCTYPE html>
<html lang="en">
    <head>
    <meta charset="UTF-8">
    <title></title>
     </head>
     <body>

     </body>
</html>
<script>
    window.onload = function(){
        var body = document.getElementsByTagName('body')[0];
        var btn = body.getElementsByTagName('button');
        for(var num = 0;num < 40;num++){
        body.innerHTML += "<button>" + "按钮" + num + "</button>";
    }
        for(var num = 0;num <= 20;num++){
            //btn[num].style.marginLeft = "15px";
            btn[num].style.position = "absolute";
            btn[num].style.top = num*30 + "px";
            btn[num].style.left = num*30 + "px";
        }

        for(var num = 21;num < 40;num++){
            //btn[num].style.marginLeft = "15px";
            btn[num].style.position = "absolute";
            btn[num].style.top = btn[40-num].style.top;
            btn[num].style.left = num*30 + "px";
        }
    };
</script>

赞 +0

添加回复

巴扎黑2017-04-10 16:26:11 2楼

<!DOCTYPE html>
<html lang="en">
<head>

    <meta charset="UTF-8">
    <title></title>
    <script>
        window.onload = function(){
            var body = document.getElementsByTagName('body')[0];
            var btn = body.getElementsByTagName('button');

            var totalButtongLength=11;
            for(var num = 0;num < totalButtongLength;num++){
                body.innerHTML += "<button>" + "按钮" +num+"</button>";
            }
            var half=parseInt(totalButtongLength/2);
            var top;
            if(totalButtongLength%2!=0){
                half=parseInt(totalButtongLength/2);
                top=half;
            }

            for(var num = 0;num<totalButtongLength;num++){
                if(num<half){
                    btn[num].style.position = "absolute";
                    btn[num].style.top = num*30 + "px";
                    btn[num].style.left = num*30 + "px";
                }else{
                    btn[num].style.position = "absolute";
                    btn[num].style.top = (totalButtongLength-1-num)*30 + "px";
                    btn[num].style.left = num*30 + "px";
                }
                if(top&&num==top){
                    btn[top].style.position = "absolute";
                    btn[top].style.top = top*30 + "px";
                    btn[top].style.left = top*30 + "px";
                }

            }


        };
    </script>
</head>
<body>

</body>
</html>

赞 +0

添加回复

PHPz2017-04-10 16:26:11 1楼

function _SetCSSStyleValue(css,clsname,style,value){
        var i;
        var rules;
        if (css.rules) rules = css.rules;
        else rules = css.cssRules;
        for (i = 0; i < rules.length; i++){
            if (rules[i].selectorText === "." + clsname){
                var s = "rules[" + i + "].style." + style + " = \"" + value + "\"";
                eval(s);
                break;
            }
        }
    }

赞 +0

添加回复

专题推荐

更多>

热门话题

热门教程

更多>