ts let vs var vs const code example
Example 1: 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 2: var vs let vs const typescript
let num1:number = 1;
function letDeclaration() {
let num2:number = 2;
if (num2 > num1) {
let num3: number = 3;
num3++;
}
while(num1 < num2) {
let num4: number = 4;
num1++;
}
console.log(num1);
console.log(num2);
console.log(num3);
console.log(num4);
}
letDeclaration();