What Does the --> "Operator" Mean in C and C++? (It's Not Real)

Quick answer: there is no --> operator in C or C++. What you're really seeing is two separate, ordinary operators sitting next to each other: the postfix decrement -- and the greater-than comparison >. The compiler parses x --> 0 as x-- > 0.

The classic example

#include <stdio.h>
int main(void) {
    int x = 10;
    while (x --> 0) {       // read as: x-- > 0
        printf("%d ", x);
    }
}
// prints: 9 8 7 6 5 4 3 2 1 0

Why the confusion?

C's tokenizer is greedy and whitespace-insensitive: x-- > 0, x --> 0, and x-->0 all tokenize identically. Visually it looks like an arrow pointing "toward zero," which is a fun mnemonic but not a real language feature — it's just -- followed by >.

Related lookalikes

• -> is a real operator: member access through a pointer, e.g. ptr->field.
• <-- is not special either; it's < followed by --.

Why it starts at 9, not 10

Postfix x-- evaluates to the value of x before decrementing, so the first comparison checks 10 > 0 (true), then afterward decrements x to 9, which is what gets printed. That's why the output starts at 9 rather than 10.

FAQ

Is --> a real C++ operator?

No. It's the decrement operator -- immediately followed by the greater-than operator >, tokenized independently by the compiler.

Does this work in other languages?

Any C-family language with a postfix decrement and a greater-than operator parses it the same way (Java, C#, JavaScript, etc.), since it's a tokenizing quirk, not a special feature.

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This article explains and expands on the community answers to the Stack Overflow question “What is the '-->' operator in C/C++?”, used under the CC BY-SA 4.0 license. Screenshot credit: Stack Exchange Inc.