Ternary Operator

The ternary operator is a shorthand way to write simple if-else statements. It's called "ternary" because it takes three operands (parts).

Basic Syntax

Copyconst age = 18

age >= 18 ? "trueValue" : "falseValue"

Think of ? as "if" and : as "else". If the condition before ? is true, it returns the value after the ?; otherwise, it returns the value after the :.

Ternaries Return Values

Another useful feature of the ternary operator is that it always returns a value. This makes it great for assignments:

Copy// Traditional if-else
let message
if (age >= 18) {
  message = "You can vote"
} else {
  message = "You cannot vote"
}

Copy// Ternary operator
const message = age >= 18 ? "You can vote" : "You cannot vote"

Chaining Ternary Operators

You can chain multiple ternaries together, but be careful as it can get hard to read:

Copy// This works but can be hard to read
const grade = score >= 90 ? "A" : score >= 80 ? "B" : score >= 70 ? "C" : "F"

// If-else is clearer
let grade
if (score >= 90) {
  grade = "A"
} else if (score >= 80) {
  grade = "B"
} else if (score >= 70) {
  grade = "C"
} else {
  grade = "F"
}

When to Use Ternary Operators

✅ Good for:

• Simple conditions with two outcomes
• Assigning values based on conditions
• Short, readable expressions

❌ Avoid for:

• Complex conditions
• Multiple statements in each branch
• Nested ternary operators

Exercise

Convert this if-else statement to a ternary operator:

Copylet weather
if (temperature > 75) {
  weather = "hot"
} else {
  weather = "not hot"
}

Copyconst weather = temperature > 75 ? "hot" : "not hot"