Error Handling in JavaScript
Error Handling
While executing the JavaScript code, different errors may occur. These errors can be a syntax error, logical error, and runtime error. There are several ways of handling them:-
The try and catch:- The try statement is a block of code that lets us test a block of code for errors, while the catch statement is a block of code that lets us handle the error.
try {
expression;
}
catch(error) {
expression;
}
var a = 10;
var b = 20;
try {
console.log(a + b);
}
catch(error) {
console.log(error);
}
The throw:- The throw statement allows us to create a custom error.
var x;
try {
if(x == "") throw "Empty";
if(isNaN(x)) throw "Not a number";
}
catch(error) {
console.log(error);
}
The finally:- The finally statement is a block of code that lets us execute code, after try and catch, regardless of the result, which means finally block will always execute.
var x;
try {
if(x == "") throw "Empty";
if(isNaN(x)) throw "Not a number";
}
catch(error) {
console.log(error);
} finally {
console.log("Finally block will always execute!")
}