C Programming Conditional Statements - Lesson 4

Conditional Programming Element - Lesson 4

• Conditional statements in C programming allow the program to execute different code blocks based on whether a condition is true or false.
• This process is also called decision making, and the decision-making statements are control statements.

Objectives

• Understand how conditional statements work in C programming.
• Differentiate between different conditional statements in C.

Conditional Programming in C

• In C programs, code is normally executed sequentially.
• A condition allows the flow of execution to change based on whether a condition is true or false.

if Statement

• Syntax:

if (test expression) 
{
/*statements to be executed if the test expression is true*/
}

• The test expression is evaluated.
• If the expression is true, the statements inside the if block are executed.
• If the expression is false, the statements inside the if block are skipped.

How if Statement Works

• The if statement checks the test expression inside the parentheses.
• If the test expression is true, the statements within the if block are executed.
• If the test expression is false, the statements within the if block are not executed.

if...else Statement

• Syntax:

if (test expression) {
/*statements to be executed if the test expression is true*/
}
else {
/*statements to be executed if the test expression is false*/
}

How if...else Statement Works

• The if statement checks the test expression. If true, the statements inside the if block are executed; otherwise, the statements inside the else block are executed.

if...else Ladder

• Allows checking multiple conditions.
• Syntax:

if (test expression1)
{
 // statements
}
else if (test expression2)
{
 // statements
}
else if (test expression3)
{
 // statements
}
else {
 // statements
}

Switch Statement

• Enables executing different code blocks based on various alternatives.
• Often easier to read than multiple if...else statements.
• Syntax:

switch (expression) {
case constant1:
// statements break;
case constant2:
// statements break;
// ...
default:
// default statements
}

How Switch Statement Works

• The Expression is evaluated
• It determines which of the case statements matches
• If a case matches, the block of code associated with that case is executed until a break statement is encountered.
• If no match is found, the default block is executed.

Examples

• Demonstrates programs to check if a number is negative, check if an integer is odd or even, create a simple calculator using conditional statements in C.

Explore the fourth lesson on conditional programming in C. Understand how conditional statements like 'if' allow for decision-making in code, changing program flow based on true or false evaluations. Differentiate between various conditional statements as you learn their syntax and applications.