Detailed explanation of try catch instances in javascript

This article mainly introduces relevant information about the summary of try catch application in javascript. Friends who need it can refer to

Summary of try catch application in javascript

Example code:

<script language="Javascript"> 
try 
{ 
throw new Error(10,"asdasdasd") 
} 
catch (e) 
{ 
alert(e.message); 
alert(e.description) 
alert(e.number) 
alert(e.name) 
throw new Error(10,"asdasdasd") 
} 

</script>

You can use try...catch in Javascript for exception handling. For example:

try {
 foo.bar();
} catch (e) {
 alert(e.name + ": " + e.message);
}

Currently, the system exceptions we may get mainly include the following 6 types:

1. ##EvalError : raised when an error occurs executing code in eval()

2. RangeError: raised when a numeric variable or parameter is outside of its valid range

3. ReferenceError: raised when de-referencing an invalid reference

4. SyntaxError: raised when a syntax error occurs while parsing code in eval()

5. TypeError: raised when a variable or parameter is not a valid type

6. URIError: raised when encodeURI() or decodeURI() are passed invalid parameters

new Error();
new Error("异常信息");

try {
 throw new Error("Whoops!");
} catch (e) {
 alert(e.name + ": " + e.message);
}

##

try {
 foo.bar();
} catch (e) {
 if (e instanceof EvalError) {
   alert(e.name + ":" + e.message);
 } 
 else if (e instanceof RangeError) {
   alert(e.name + ": " + e.message);
 } 
 // etc 
}

description: Error description (only available in IE).
fileName: Error file name (only available in Mozilla).
lineNumber: The number of lines with errors (only available in Mozilla).
message: Error message (same description under IE)
name: Error type.
number: Error code (only available in IE).
stack: Like Stack in Java Trace the same error stack information (only available to Mozilla).

7. 
   

So in order to better understand the error message, we can change the catch part to the following form:

try {
 foo.bar();
} catch (e) {
 if (browserType != BROWSER_IE) {                
   alert("name: " + e.name + 
   "message: " + e.message + 
   "lineNumber: " + e.lineNumber + 
   "fileName: " + e.fileName + 
   "stack: " + e.stack);      
 } 
 else {            
   alert("name: " + e.name +    
   "errorNumber: " + (e.number & 0xFFFF ) + 
   "message: " + e.message");      
 } 
}

try {
 throw new Date(); // 抛出当前时间对象 
} catch (e) {
 alert(e.toLocaleString()); // 使用本地格式显示当前时间 
}

The above is the detailed content of Detailed explanation of try catch instances in javascript. For more information, please follow other related articles on the PHP Chinese website!