🧩 C Operator Precedence – Complete Table with Examples
🧲 Introduction – What Is Operator Precedence in C?
Operator precedence in C defines the order in which operators are evaluated in complex expressions. When multiple operators appear in a single expression, precedence determines which operations are performed first—just like the order of operations in mathematics (e.g., multiplication before addition).
🎯 In this guide, you’ll learn:
- What operator precedence and associativity mean
- Complete table of C operator precedence
- Examples where precedence affects result
- Best practices using parentheses for clarity
🔍 What Is Precedence and Associativity?
- Precedence determines which operator is evaluated first.
- Associativity determines the direction of evaluation (left-to-right or right-to-left) when operators have the same precedence.
✅ Example:
int result = 5 + 2 * 3; // result = 11 (not 21)
Here, * has higher precedence than +.
📚 C Operator Precedence Table (Highest to Lowest)
| Precedence | Operators | Associativity | Description |
|---|---|---|---|
| 1 | () [] -> . | Left to Right | Function call, array, struct access |
| 2 | ++ -- + - ! ~ * & sizeof | Right to Left | Unary, address-of, dereference |
| 3 | * / % | Left to Right | Multiplication, division, modulus |
| 4 | + - | Left to Right | Addition, subtraction |
| 5 | << >> | Left to Right | Bitwise shift left, right |
| 6 | < <= > >= | Left to Right | Relational operators |
| 7 | == != | Left to Right | Equality/inequality |
| 8 | & | Left to Right | Bitwise AND |
| 9 | ^ | Left to Right | Bitwise XOR |
| 10 | ` | ` | Left to Right |
| 11 | && | Left to Right | Logical AND |
| 12 | ` | ` | |
| 13 | ?: | Right to Left | Ternary conditional |
| 14 | = += -= *= /= etc. | Right to Left | Assignment |
| 15 | , | Left to Right | Comma (sequence) |
🧪 Examples of Operator Precedence
🔹 Without Parentheses
int a = 10, b = 5, c = 2;
int result = a + b * c; // b * c = 10, then 10 + 10 = 20
🔹 With Parentheses
int result = (a + b) * c; // a + b = 15, then 15 * 2 = 30
🔁 Associativity Example
int a = 5;
int result = a = a + 2 * 3; // 2 * 3 = 6, then a + 6 = 11, then a = 11
In a = a + 2 * 3;, the * is evaluated first, then +, then =.
💡 Best Practices
- ✅ Always use parentheses to clarify the intended order.
- ✅ Avoid writing complex one-liners with multiple operators.
- ✅ Use indentation and line breaks for readability when needed.
- ⚠️ Don’t assume operator precedence—look it up or add parentheses.
📌 Summary – Recap & Next Steps
Operator precedence and associativity in C are vital for writing correct and predictable expressions. Misunderstanding precedence can lead to logical errors and unexpected results.
🔍 Key Takeaways:
- Precedence defines which operators are evaluated first.
- Associativity defines direction (left-to-right or right-to-left).
- Use parentheses to control or override the default precedence.
- Multiplication and division have higher precedence than addition/subtraction.
⚙️ Real-World Relevance:
Operator precedence is crucial in expression-heavy code, such as mathematical computations, conditional logic, algorithm design, and embedded C programming where performance and correctness matter.
❓ Frequently Asked Questions (FAQ)
❓ What is operator precedence?
✅ It determines the priority of operators in expressions without parentheses. Operators with higher precedence are evaluated before lower ones.
❓ What is operator associativity?
✅ When multiple operators with the same precedence appear, associativity defines the evaluation direction—usually left-to-right.
❓ How do I ensure correct evaluation?
✅ Use parentheses () to explicitly define the order of operations:
int result = (a + b) * c;
❓ Does && have higher precedence than ||?
✅ Yes. Logical AND (&&) has higher precedence than Logical OR (||).
❓ Can I rely on operator precedence across compilers?
✅ Yes. C operator precedence is defined by the language standard and behaves the same across standard-compliant compilers.
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