JavaScript: conditionals

Conditional statements choose which code runs based on whether an expression is true or false.

What you will learn

How if, else if, and else work
How strict comparison and boolean values affect a branch
When a switch statement is useful

Minimal example

const score = 72;
if (score >= 80) {
  console.log('Great');
} else if (score >= 60) {
  console.log('Pass');
} else {
  console.log('Try again');
}

Conditions are evaluated from top to bottom. Once a matching branch runs, the remaining branches are skipped.

Common mistakes

Prefer === and !== when comparing values without implicit type conversion.
Remember that empty strings, 0, false, null, and undefined are falsy.
Use braces even for short branches so later edits do not change the intended scope.