js捕获错误的两种方法

方法一：try ... catch ...

< script >
function reportErr( errMsg)
{
alert ( errMsg) ;
//... ...
}


//test
try {
arr[ 8] = sdalf;
} catch ( e ) {
reportErr( e ) ;
}
< / script >

方法二：window.onerror = ...

< script >
function fetchError( )
{
var arglen = arguments . length ;
var errorMsg = "argc: " + arglen;
for ( var i= 0; i< arglen; i+ + ) {
errorMsg + = "/narg " + ( i+ 1) + ": " + arguments [ i] ;
}
reportErr( errorMsg) ;
window . onerror = null ;
return true ;
}
function reportErr( errMsg)
{
alert ( errMsg) ;
//... ...
}
window . onerror = fetchError;


//test
arr[ 8] = sdalf;
< / script >