When to use semicolon in JavaScript?

Semicolon is optional, except when you need to separate multiple statements on the same line:

• In a for loop
• When declaring multiple variables on the same line
• When executing multiple statements on the same line

In a for loop

for (let i = 0; i < 10; i++) { // <- here
  if (i === 5) {
    console.log('Hello World!')
  }
}

Declaring multiple variables on the same line

const a = 1; const b = 2; const c = 3 // <- here

console.log(a) // 1
console.log(b) // 2
console.log(c) // 3

Executing multiple statements on the same line

let a = 1

a++; a = a * 5; console.log(a) // <- here (logs 10)