JavaScript If and Else

JavaScript If and Else

Use if and else to make decisions in your code.

The if statement

if (age >= 18) {
  console.log("Adult");
}

If the condition in parentheses is true, the code in the block runs.

if and else

if (hour < 12) {
  console.log("Good morning");
} else {
  console.log("Good afternoon");
}

If the condition is false, the else block runs instead.

else if

Check multiple conditions in order:

if (score >= 90) {
  console.log("A");
} else if (score >= 80) {
  console.log("B");
} else {
  console.log("Try again");
}

JavaScript checks each condition from top to bottom and runs the first one that is true.

Comparison conditions

Conditions usually use comparison operators like ===, >, <, and logical operators like && and ||.

TL;DR

• if runs code when a condition is true.
• else runs when the condition is false.
• else if checks more conditions in order.
• Only the first true block runs.