if, else if, else Statements

Conditionals let your program make decisions. The if statement runs code only when a condition is true. else runs when false. else if checks additional conditions. This is how programs respond differently to different inputs.

15 min•By Priygop Team•Updated 2026

Conditional Logic

if (condition) { } — Runs code block if condition is true
else { } — Runs if the condition is false
else if (condition) { } — Checks another condition if the first was false
You can chain multiple else if blocks — only the first matching block executes
Conditions use comparison operators: >, <, ===, !==, >=, <=
Combine conditions with && (AND) and || (OR)

if/else Code

// Basic if/else
const age = 18;

if (age >= 18) {
  console.log("You can vote! ✅");
} else {
  console.log("Too young to vote ❌");
}

// else if chain
const score = 75;
if (score >= 90) {
  console.log("Grade: A — Excellent!");
} else if (score >= 80) {
  console.log("Grade: B — Great!");
} else if (score >= 70) {
  console.log("Grade: C — Good");
} else if (score >= 60) {
  console.log("Grade: D — Needs work");
} else {
  console.log("Grade: F — Please study more");
}

// Combined conditions
const hasID = true;
const isAdult = age >= 18;

if (isAdult && hasID) {
  console.log("Entry allowed");
} else {
  console.log("Entry denied");
}

Try It Yourself: Grade Calculator

Try It Yourself: Grade CalculatorJavaScript

JavaScript Editor

✓ ValidTab = 2 spaces

// Change the score and see the grade!
const score = 85;
console.log("Score:", score);

if (score >= 90) {
  console.log("Grade: A — Excellent!");
} else if (score >= 80) {
  console.log("Grade: B — Great!");
} else if (score >= 70) {
  console.log("Grade: C — Good");
} else {
  console.log("Grade: F — Study more");
}

// Even/Odd checker
const number = 7;
if (number % 2 === 0) {
  console.log(number + " is Even");
} else {
  console.log(number + " is Odd");
}

Result

Click ▶ Run to see the result

Edit the code on the left, then click Run (Ctrl+Enter)

JavaScript|21 lines|464 chars|✓ Valid syntax

UTF-8

Tip

Store conditions in descriptive boolean variables before using them in if statements. Instead of if (age >= 18 && hasID && !isBanned), write const canEnter = age >= 18 && hasID && !isBanned; if (canEnter) — much more readable.

Diagram

Loading diagram…

?? only checks null/undefined, || checks all falsy.

Common Mistake

Warning

Using = (assignment) instead of === (comparison) inside if conditions. if (x = 5) assigns 5 to x and always evaluates as truthy. Always use === for comparisons: if (x === 5).

Practice Task

Note

Build a ticket pricing system: (1) If age < 5, free entry. (2) If age < 18, half price. (3) If age >= 65, senior discount. (4) Otherwise, full price. Test with ages 3, 12, 25, and 70.

Quick Quiz

Key Takeaways

Conditionals let your program make decisions.
if (condition) { } — Runs code block if condition is true
else { } — Runs if the condition is false
else if (condition) { } — Checks another condition if the first was false

Topics in This Module