Hello! Welcome to my first post, and thank you for checking out my blog. We are going to start with something simple: the different ways to declare variables in JavaScript.
There are three ways to declare variables in JavaScript, and those are let, const, and var. Today we will just be covering let and const, which were introduced in 2015 and are now used much more often than var.
let
Using let allows us to declare a variable that we may want to change the value of at a later time. You can declare a variable using let without immediately assigning it a value.
let dog;
//=> undefined
Later you could assign a value to your variable with the following syntax:
dog = 'Ted';
//=> Ted
dog;
//=> Ted
When using let, you can assign a different value to the variable at any time.
dog;
//=> Ted
dog = 'Libby';
dog
//=> Libby
const
We use const when we want to assign a value to a variable that will remain constant throughout our code. You cannot reassign a variable declared with const, and its value must be set when declaring the variable.
const breed = 'chihuahua';
//=>undefined
breed;
//=> chihuahua
breed = 'beagle'
//=> Uncaught TypeError: Assignment to constant variable.
If you try to declare a variable using const without assigning a value, you will get an error message.
const breed
//=> Uncaught SyntaxError: Missing initializer in const declaration
I hope this helped you learn more about different ways to declare a variable in JavaScript, and when to use let and when to use const. Thanks for reading!
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