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JAVASCRIPT TUTORIALS - Javascript - Error Handling

Javascript - Error Handling

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<script type="text/javascript">
<!--
window.print(;
//-->
</script>

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<script type="text/javascript">
<!--
window.printme();
//-->
</script>

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<script type="text/javascript">
<!--
try {
    // Code to run
    [break;]
} catch ( e ) {
    // Code to run if an exception occurs
    [break;]
}[ finally {
    // Code that is always executed regardless of 
    // an exception occurring
}]
//-->
</script>

Examples:


<html>
<head>
<script type="text/javascript">
<!--
function myFunc()
{
   var a = 100;

   alert("Value of variable a is : " + a );
 
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<html>
<head>
<script type="text/javascript">
<!--
function myFunc()
{
   var a = 100;
   
   try {
      alert("Value of variable a is : " + a );
   } catch ( e ) {
      alert("Error: " + e.description );
   }
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<html>
<head>
<script type="text/javascript">
<!--
function myFunc()
{
   var a = 100;
   
   try {
      alert("Value of variable a is : " + a );
   }catch ( e ) {
      alert("Error: " + e.description );
   }finally {
      alert("Finally block will always execute!" );
   }
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<html>
<head>
<script type="text/javascript">
<!--
function myFunc()
{
   var a = 100;
   var b = 0;
   
   try{
      if ( b == 0 ){
         throw( "Divide by zero error." ); 
      }else{
         var c = a / b;
      }
   }catch ( e ) {
      alert("Error: " + e );
   }
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<html>
<head>
<script type="text/javascript">
<!--
window.onerror = function () {
   alert("An error occurred.");
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<html>
<head>
<script type="text/javascript">
<!--
window.onerror = function (msg, url, line) {
   alert("Message : " + msg );
   alert("url : " + url );
   alert("Line number : " + line );
}
//-->
</script>
</head>
<body>
<p>Click the following to see the result:</p>
<form>
<input type="button" value="Click Me" onclick="myFunc();" />
</form>
</body>
</html>


<img src="myimage.gif"
    onerror="alert('An error occurred loading the image.')" />