If I wanted to implement a variable check whenever I was to use the .indexOf() method of javascript would it be possible?
For example, using a.indexOf(b); can detect when a is null or undefined and change method to return -1 ?
Can not extend null or a variable that is undefined . That is if you have:
a.indexOf(b);
If a is null or undefined this will give error.
Solutions?!
A variant is to use try{}catch(e){} in this way you create a safe zone where you can run code without stopping execution because of errors.
var result;
try{
result = a.indexOf(b);
} catch(){
result = -1;
}
Another option is to create a function to do this.
function indexOf(str, el){
if (!str && str != 0) return -1;
return str.indexOf(el);
}
var result = indexOf(a, b);