Expressions and Statements in C

Expression

A combination of operands and operators that produces a value is called an expression.

c = a + b;

Part	Role
`a` and `b`	Operands
`+`	Arithmetic operator
`=`	Assignment operator
`a + b`	Expression (evaluates to a value)

More examples:

x * y          // arithmetic expression
x > y          // relational expression (true/false)
x && y         // logical expression
x = 5          // assignment expression — returns 5

Statement

A statement is a complete instruction in C that performs an action. Most statements end with a semicolon (;).

Types of Statements

Declaration Statement — creates a variable:

int x;

Assignment Statement — assigns a value:

x = 10;

Expression Statement — evaluates an expression:

a + b;
x++;

Function Call Statement — calls a function:

printf("Hello");
scanf("%d", &x);

Control Flow Statement — changes execution order:

if (x > 0) { ... }
while (x < 10) { ... }
for (int i = 0; i < 5; i++) { ... }

Compound Statement (Block) — a group of statements enclosed in {}:

{
    int a = 5;
    int b = 10;
    int c = a + b;
}

A block is treated as a single unit. Variables declared inside a block are local to that block.

Key Difference

	Expression	Statement
Definition	Produces a value	Performs an action
Example	`a + b`	`int a = 5;`
Ends with	No semicolon needed	Semicolon `;`

Fundamentals

Functions

Array

String

Structure

Union

Pointer

File Handling

Preprocessor

Expressions and Statements

Expressions and Statements in C

Expression

Statement

Types of Statements

Key Difference

​Expressions and Statements in C

​Expression

​Statement

​Types of Statements

​Key Difference

Expressions and Statements in C

Expression

Statement

Types of Statements

Key Difference