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<html><head><meta charset="UTF-8"><title>求平方根</title><script type="text/javascript">window.onload=function(){//获取页面的元素var num=document.getElementById("num");var btn=document.getElementById("btn");var msg=document.getElementById("msg");var count=0;//声明一个变量用于计算循环的次数var square=-1;//声明一个变量存储平方根//页面的点击事件btn.onclick=function(){for(var i=0;i<=num.value;i++){count++;if(i*i<=num.value)//判断平方根是否小于等于用户输入的内容{square=i;continue;}msg.innerHTML="循环体执行了"+count+"次"count=0;break}if(square!=-1){msg.innerHTML+="完成"+num.value+"近似平方根是"+square+"和"+(-square)}}}</script></head><body><label for="">请输入一个正整数：</label><input type="text" id="num" value="" /><button id="btn">计算</button><div id="msg"></div></body>
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![[从零开始学算法]求平方根](https://img-blog.csdnimg.cn/20200608235234424.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3RpbWVfbGltaXRlZA==,size_16,color_FFFFFF,t_70)
