In this article I will be showing you some awesome 🔥🔥 JavaScript tricks that you probably didn't knew about....

These tricks will help you in writing competitive JavaScript and much more....

1. Use Strict

If you have some basic knowledge of TypeScript, then you must be knowing about this.

Use Strict enables strict mode in JavaScript

• Does not allow the use of undeclared variables
• Will make you write more secure 🔐 JavaScript
• Deleting a variable or object is not allowed
• And many more things...

How to enable Strict Mode

// Add this line of code at the start of your *.js file

"use strict";

For more information look into the article on W3school

2. You don't really need semi-colon “;”

Yeah, you heard that right...
JavaScript adds semicolons where it is needed and it doesn't find any.

But this semicolon adding does not work as needed sometimes and can give you unnecessary errors ❌. I prefer to keep them, because I don't want to take any chances. You can check more about this here

3. Run a function at the time of declaration

Known as the self calling functions or also Immediately Invoked Function Expression (IIFE). It is a function which automatically executes when you create it.

Examples

// Example 1
(function(){
    console.log("This is an example of IIFE function");
})();

// Example 2: This function prints sum of two numbers
(function(a,b){
     console.log(a+b);
})(10,35);

4. Throw custom Errors

Yes!! This is possible in JavaScript, you can throw your own exceptions.

You will mostly use this while debugging, when wrong parameters are passed to a function or according to your wish :)...

Syntax of throwing custom errors...

function divide(dividend, divisor){
    // The divisor should not be 0 according to the rules of mathematics
    // Also we need to check if both dividend and divisor are number
    if(typeof divisor != "number")
         throw new Error("Typeof divisor is not a number");
    if(typeof dividend != "number")
         throw new Error("Typeof dividend is not a number");
    if(divisor === 0)
         throw new Error("Divisor cannot be equal to 0");

    return dividend/divisor;
}

5. Using block scope to create temporary variables

Block scope can be very useful to avoid any unnecessary memory.

Example:

{
    let a = "Hello";
    console.log(a);
    // Expected output "Hello"
}
console.log(a);     // undefined

Note: var is function scope, declaring variables with 'var' will not be block scoped. Use 'let' for declaring block scoped variables

So, that's all for today guys.

Hope you liked my article... If so drop a ❤️ and 👍.

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