CBasics

C Control Statements (if, else, switch)

Learn C control statements such as if, else, else-if, and switch to control the flow of execution and make decisions in C programs.

What are Control Statements in C?Link to this section

Control statements are used to control the flow of execution in a C program. They allow the program to make decisions and execute different blocks of code based on conditions. By default, C programs execute statements sequentially. Control statements change this normal flow.

Types of Control Statements :Link to this section

C provides several control statements, including:
  • if statement
  • if–else statement
  • else-if ladder
  • switch statement

The " if "Statement :Link to this section

The if statement executes a block of code only when a given condition is true.
Explanation: If the condition evaluates to true, the code inside the if block runs.

The " if–else " Statement :Link to this section

The if–else statement provides an alternative block of code when the condition is false.

The " else-if " Ladder :Link to this section

When multiple conditions need to be checked, the else-if ladder is used.

note

Conditions are evaluated from top to bottom. Once a true condition is found, the remaining conditions are skipped.

The switch Statement :Link to this section

The switch statement is used when a variable is compared against multiple fixed values.
Explanation:
  • case specifies a value
  • break stops execution
  • default runs if no case matches

Importance of the " break "Statement :Link to this section

The break statement prevents fall-through, where multiple cases execute unintentionally.

warning

Omitting break can cause unexpected results.

When to Use if–else vs switch :Link to this section

Use if–else when

- Conditions involve ranges - Logical operators are required

Use switch when

- Comparing a single variable - Checking fixed constant values

Why Control Statements are Important :Link to this section

Control statements allow programs to:
  • Make decisions
  • Handle different scenarios
  • Implement business logic

tip

Most real-world programs rely heavily on control statements.
Check Your Understanding
Question 1 of 5

Which statement executes code only when a condition is true?

Practice Challenges

medium
  • Write a program to check whether a number is positive, negative, or zero.
  • Create a grading system using else-if ladder.
  • Use switch to display the name of the day based on a number.
  • Convert an if–else ladder into a switch statement where possible.
  • Predict the output of a switch statement with missing break.