Useful any time you want to know what the first N characters or last N characters of a string are.
For example, if you have a code that is made up of two parts like "ABCD-12345" and you need to break it into "ABCD" or "12345", you can use these functions.
function Left(str, n){
if (n <= 0)
return "";
else if (n > String(str).length)
return str;
else
return String(str).substring(0,n);
}
function Right(str, n){
if (n <= 0)
return "";
else if (n > String(str).length)
return str;
else {
var iLen = String(str).length;
return String(str).substring(iLen, iLen - n);
}
}