明明就得不到正确结果
课程页地址:http://www.imooc.com/code/1488
<!DOCTYPE html> <html> <head> <title> 事件</title> <script type="text/javascript"> function count(){ var first = document.getElementById("txt1").value; var sec = document.getElementById("txt2").value; var result ; //获取第一个输入框的值 //获取第二个输入框的值 //获取选择框的值 var selec = document.getElementById("select").value; //获取通过下拉框来选择的值来改变加减乘除的运算法则 if (select === "+"){ result = first + sec; } else if (select === "-" ){ result = first - sec; } else if (select ==="*"){ result = first * sec; } else if (select === "/") { result = first / sec; } //设置结果输入框的值 var theResult = document.getElementById("fruit"); theResult.value = result; } </script> </head> <body> <input type='text' id='txt1' /> <select id='select'> <option value='+'>+</option> <option value="-">-</option> <option value="*">*</option> <option value="/">/</option> </select> <input type='text' id='txt2' /> <input type='button' value=' = ' onclick = "count()" /> <!--通过 = 按钮来调用创建的函数,得到结果--> <input type='text' id='fruit' /> </body> </html>
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isu_腾飞
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