Leslie继续宠爱
2015-01-24 21:41
<!DOCTYPE html> <html> <head> <title> 事件</title> <script type="text/javascript"> function count(){ var m=document.getElementById("txt1").value; var b=document.getElementById("txt2").value; var c =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 var result=""; switch(c){ case '+': result=parseInt(m)+parseInt(b) ; break; case '-': result=parseInt(m)-parseInt(b); break; case '*': result=parseInt(m)*parseInt(b) ; break; default '/': result=parseInt(m)/parseInt(b) ; break; } document.getElementById("fruit")=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>
简单来说 document.getElementById("fruit")=result;少个.value
default '/':
result=parseInt(m)/parseInt(b) ;
break;
default应该改成case
<!DOCTYPE html> <html> <head> <title> 事件</title> <script type="text/javascript"> function count(){ var m=document.getElementById("txt1").value; var b=document.getElementById("txt2").value; var c =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 var result="0"; switch(c){ case '+': alert("+++"); result=parseInt(m)+parseInt(b) ; break; case '-': result=parseInt(m)-parseInt(b); break; case '*': result=parseInt(m)*parseInt(b) ; break; case '/': result=parseInt(m)/parseInt(b) ; break; } alert(result); document.getElementById("fruit").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();"/> <input type='text' id='fruit' /> </body> </html>
JavaScript进阶篇
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