js学习-数据类型转换小案例

    技术2024-06-30  76

    <!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 oUl = document.getElementById('list'); var aLi = oUl.getElementsByTagName('li'); for( var i=0; i<aLi.length; i++ ){ fn1(aLi[i]); } function fn1(oLi){ var aBtn = oLi.getElementsByTagName('input'); var oStrong = oLi.getElementsByTagName('strong')[0]; var oEm = oLi.getElementsByTagName('em')[0]; var oSpan = oLi.getElementsByTagName('span')[0]; var n1 = Number(oStrong.innerHTML); // '0' => 0 var n2 = parseFloat(oEm.innerHTML); // '12.5元' => 12.5 aBtn[0].onclick = function (){ n1 --; if ( n1 < 0 ) { n1 = 0; } oStrong.innerHTML = n1; oSpan.innerHTML = n1*n2 + '元'; }; aBtn[1].onclick = function (){ n1 ++; oStrong.innerHTML = n1; oSpan.innerHTML = n1*n2 + '元'; }; } }; </script> </head> <body> <ul id="list"> <li> <input type="button" value="-" /> <strong>0</strong> <input type="button" value="+" /> 单价:<em>12.5元</em> 小计:<span>0元</span> </li> <li> <input type="button" value="-" /> <strong>0</strong> <input type="button" value="+" /> 单价:<em>10.5元</em> 小计:<span>0元</span> </li> <li> <input type="button" value="-" /> <strong>0</strong> <input type="button" value="+" /> 单价:<em>8.5元</em> 小计:<span>0元</span> </li> <li> <input type="button" value="-" /> <strong>0</strong> <input type="button" value="+" /> 单价:<em>8元</em> 小计:<span>0元</span> </li> <li> <input type="button" value="-" /> <strong>0</strong> <input type="button" value="+" /> 单价:<em>14.5元</em> 小计:<span>0元</span> </li> </ul> <p> 商品合计共:0件,共花费了:0元<br /> 其中最贵的商品单价是:0元 </p> </body> </html>

    通过按钮改变数量,统计出总价

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