Java With Us

The Ternary Operator <code>?:</code> in Java

Updated on 2026-04-21 Reviewed by the Java With Us editorial team

The ternary operator ?: is the only operator in Java that takes three operands. It evaluates a boolean condition and returns one of two values depending on the outcome. Unlike if/else, it's an expression — useful inside assignments, method arguments, and return statements.

Syntax

result = condition ? valueIfTrue : valueIfFalse;

Examples

String s = active ? "ON" : "OFF";
int abs  = n >= 0 ? n : -n;

return user == null ? "anon" : user.name();

send(amount > 0 ? amount : 0);

Type rules

The two result expressions must share a common type. For references the result is the nearest common supertype; for primitives Java applies numeric promotion:

Object o = cond ? "string" : 42;         // ✅ common type is Object
int    n = cond ? 1 : 2.0;               // ❌ different — would need a cast
double x = cond ? 1 : 2.0;               // ✅ 1 is promoted to double

Autoboxing pitfall

Integer boxed = null;
int prim = cond ? boxed : 0;             // NPE if cond is true — unboxes null

If one branch is a primitive and the other is a wrapper, Java unboxes the wrapper — and null crashes.

Chains are usually a mistake

// ❌ hard to read
var label = score > 90 ? "A" : score > 80 ? "B" : score > 70 ? "C" : "F";

// ✅ switch expression (Java 14+)
var label = switch ((int) score / 10) {
    case 10, 9 -> "A";
    case 8     -> "B";
    case 7     -> "C";
    default    -> "F";
};

Optional replaces many null-ternaries

String name = user != null ? user.name() : "anon";

// With Optional
String name = Optional.ofNullable(user).map(User::name).orElse("anon");

Common mistakes

  • Nested ternaries — switch to if/else or a switch expression after one level.
  • Autoboxing NPE — match the types of both branches.
  • Side effects in the branches — ternaries are expressions, not control flow. Keep them pure.

Related

Pillar: Java control flow. See also operators: ternary, switch expression.

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