const vs let javascript code example
Example 1: let vs const
`const` is a signal that the identifier won't be reassigned.
`let` is a signal that the variable may be reassigned, such as a counter in a
loop, or a value swap in an algorithm.
It also signals that the variable will be used only in the block it's defined
in, which is not always the entire containing function.
Example 2: var vs let vs const
var:
- hoisted (always declared at top of scope, global if none)
- function scope
let:
- block scope
- not redeclarable
const:
- block scope
- not reassignable
- not redeclarable
Note: Although it may seem like these hold only semantic meaning, using the
appropriate keywords helps the JS engines' compiler to decide on what to optimize.
Example 3: what is the difference between let and const in javascript
The difference is that with const you can only only assign a value to a variable
once, but with let it allows you to reassign after it has been assigned.
Example 4: var or const in javascript
const myConst='A const does not change.';
var myVar='A var does change.';
var myVar=2;