Operators & Expressions in C

Introduction

In C programming, operators are symbols that perform operations on variables and values. An expression is a combination of operators, constants, and variables that evaluates to a single value. Understanding operators and expressions is crucial for writing logical and effective programs.

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Key Points

1. Types of Operators

1. Arithmetic Operators

• Perform basic mathematical operations: +, -, *, /, %
• Example: int a = 10, b = 3; printf("%d", a % b); // Output: 1

2. Relational Operators

• Compare values and return true (1) or false (0)
• Operators: ==, !=, >, <, >=, <=
• Example: if(a > b) { /* code */ }

3. Logical Operators

• Combine multiple conditions: && (AND), || (OR), ! (NOT)
• Example: if(a > 5 && b < 10) { /* code */ }

4. Assignment Operators

• Assign values to variables: =, +=, -=, *=, /=
• Example: a += 5; // a = a + 5

5. Increment & Decrement Operators

• ++ → increment by 1
• -- → decrement by 1
• Can be prefix (++a) or postfix (a++)

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2. Expressions

• Definition: Combination of variables, constants, and operators that evaluates to a value
• Examples: int x = 10 + 5; // 15 int y = x * 2; // 30
• Importance:
  • Expressions form the logic of programs
  • Used in calculations, conditions, and loops

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3. Operator Precedence

• Determines the order in which operators are evaluated
• Example: int x = 10 + 5 * 2; → 5*2 evaluated first → x = 20

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Example Code

#include <stdio.h>
int main() {
    int a = 10, b = 5;
    int sum = a + b;
    int isEqual = (a == b);
    int result = (a > 5 && b < 10);
    printf("Sum: %d, Equal: %d, Result: %d", sum, isEqual, result);
    return 0;
}