Question

我编写简单的Javascript除法函数并进行异常处理使用throw，try()和catch()问题是代码有异常根本不工作甚至没有显示

这是我的代码

<html>
    <head>
        <title>JavaScript lab</title>
        <meta charset="utf-8" />
        <script language="javascript">

            function div(a,b) { 
              if (b == 0)
                throw { name: 'notallowed', message: 'div by zero' };
                var c = a/b;
                alert(c);
              }
            }

            try {
              var x = prompt("Enter num1"); 
              var y = prompt("Enter num2"); 

              div(a,b);
            }
            catch(e) {
              alert("Error: "+e.message);
            }

        </script>
    </head>
</html>

Answer 1

可能这样可以正常工作

function div(a,b) { 
   if (b == 0){
       throw { name: 'notallowed', message: 'div by zero' };
   }
   var c = a/b;
   alert(c);
}

{

结束时您错过了if(b==0)

Answer 2

//modify 
function div(a,b) { //function div(a,b)
  if (b == 0){
    throw { name: 'notallowed', message: 'div by zero' };
     var c = a/b;
    alert(c);
  }
}


try {
  var x = prompt("Enter num1"); 
  var y = prompt("Enter num2"); 

  //modify
  div(x,y);//div(a,b);
}
catch(e) {
  alert("Error: "+e.message);
}

Answer 3

这应该有效

        function div(a,b) { 
          if (b == 0) {
            throw { name: 'notallowed', message: 'div by zero' };
          }
          var c = a/b;
          alert(c);
        }


        try {
          var x = prompt("Enter num1"); 
          var y = prompt("Enter num2"); 

          div(x,y);
        }
        catch(e) {
          alert("Error: "+e.message);
        }

javascript中的简单异常导致代码无法正常工作

3 个答案: