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Difference Between If Else and Switch

Conditional statements are essential building blocks in programming, allowing for decision-making based on specific conditions. Here is the key difference between if-else and switch conditional statements. By understanding their unique features and use cases, programmers can make more knowledgeable decisions and write more efficient programs. 

What is If-Else?

Let us first understand the If-Else statement before diving into the difference between if-else and switch.

The if-else statement is a conditional statement that executes a specific block of code based on whether a condition is true or false. When the condition is true, the block code within the "if" block is executed. Conversely, when the condition is false, the block code within the "else" block is executed.

Features of If-Else

1. Multiple Choices: If-else statements can handle multiple conditions or choices using nested if-else statements.

2. Various Data Types: If-else statements evaluate data types, including integers, characters, pointers, floating-point numbers and Booleans.

3. Equality and Logical Expressions: If-else statements test both equality expressions and logical expressions.

4. Two-way Branching: If-else statements provide a two-way branching mechanism, with one block of code executed for true conditions and another for false conditions.

5. Flexibility: If-else statements offer flexibility in decision-making, as they are with different conditions and expressions.

Syntax of If-Else Statement

if (condition) {
    // code block to be executed if the condition is true
} else {
    // code block to be executed if the condition is false
}

Examples of If-Else Statements

Example 1:

int age = 20;
if (age >= 18) {
    cout << "You are eligible to vote.";
} else {
    cout << "You are not eligible to vote.";
}

Output:

You are eligible to vote.

Explanation: In this example, the condition checks whether the age is greater than or equal to 18. As the age is 20, the condition is true and the statement "You are eligible to vote." is printed.

Example 2:

int number = -5;
if (number > 0) {
    cout << "The number is positive.";
} else {
    cout << "The number is negative.";
}

Output:

The number is negative.

Explanation: Here, the condition checks whether the number is greater than 0. As the number is -5, the condition is false and the message "The number is negative." is printed.

Example 3:

bool is_raining = true;
if (is_raining) {
    cout << "Bring a raincoat, it's raining outside.";
} else {
    cout << "No need for a raincoat.";
}

Output:

Bring a raincoat, it's raining outside.

Explanation: In this example, the condition checks the Boolean value. As it is true, the statement "Bring a raincoat." is printed.

What is a Switch Case?

A switch case statement is a type of conditional statement that checks the value of a variable against multiple cases. When a case is matched, the block code associated with the case is executed. Each case has a name or number known as an identifier and if no case is matched, the default case is executed. 

Features:

1. Single Expression: Switch cases use a single expression to evaluate multiple choices.

2. Integer and Character Data Types: Switch cases can only evaluate integer and character data types.

3. Equality Expressions: Switch cases test only equality expressions, not logical expressions.

4. Multi-way Branching: Switch cases provide multi-way branching, with different blocks of code executed for different case values.

5. Jump Table: Switch cases create a jump table during compilation, which leads to faster execution compared to nested if-else statements.

Syntax of the Switch Statement

switch (expression) {
    case constant1:
        // code block for case 1
        break;
    case constant2:
        // code block for case 2
        break;
    // ... other cases
    default:
        // code block if no case is matched
}

Examples of Switch Statement

Example 1:

int day = 3;
switch (day) {
    case 1:
        cout << "Monday";
        break;
    case 2:
        cout << "Tuesday";
        break;
    case 3:
        cout << "Wednesday";
        break;
    case 4:
        cout << "Thursday";
        break;
    case 5:
        cout << "Friday";
        break;
    case 6:
        cout << "Saturday";
        break;
    case 7:
        cout << "Sunday";
        break;
    default:
        cout << "Invalid day";
}

Output:

Wednesday

Explanation: In this example, the switch case evaluates the value of the day variable. Since the value is 3, the case 3 block is executed, and "Wednesday" is printed.

Example 2:

char grade = 'B';
switch (grade) {
    case 'A':
        cout << "Excellent";
        break;
    case 'B':
        cout << "Good";
        break;
    case 'C':
        cout << "Average";
        break;
    case 'D':
        cout << "Poor";
        break;
    case 'F':
        cout << "Fail";
        break;
    default:
        cout << "Invalid grade";
}

Output:

Good

Explanation: Here, the switch case evaluates the value of the grade variable. Since the value is 'B', the case 'B' block is executed and the statement "Good" is printed.

Example 3:

int num = 5;
switch (num) {
    case 1:
    case 3:
    case 5:
    case 7:
    case 9:
        cout << "Odd number";
        break;
    case 2:
    case 4:
    case 6:
    case 8:
    case 10:
        cout << "Even number";
        break;
    default:
        cout << "Not in range";
}

Output:

Odd number

Explanation: In this example, the switch case evaluates the value of the num variable. Since the value is 5, the case 5 block is executed and the "Odd number" output is printed.

Key Advantages of Switch Over If-Else Ladder

1. Faster Execution: Switch cases create a jump table during compilation, resulting in faster execution compared to nested if-else statements.

2. Readability: Switch cases are more readable than if-else statements, especially for large sets of values.

3. Ease of Editing: Switch cases are easier to edit and maintain compared to nested if-else statements.

4. Multi-way Branching: Switch cases provide multi-way branching, allowing for more efficient handling of multiple conditions.

5. Single Expression: Switch cases use a single expression for multiple choices, simplifying code structure.

Difference Between If Else and Switch Statement

Here is a detailed difference between if'' and switch statement in tabular form to understand the if-else to switch case in c statements properly.

Parameter

If-else

Switch

Definition

Executes if or else block depending on the condition in the if statement

Executes code block corresponding to the matched case

Evaluation

Used for integer, character, pointer, floating or Boolean type

Used for character expressions and integers

Testing

Tests both logical expressions and equality

Tests only equality

Expression

Multiple statements for multiple decisions

Single statements for multiple decisions

Default Execution

Executes else block if the condition inside the if-statement is false

Executes default statement if the condition inside the statements does not match any cases

Sequence of Execution

Executes either the if statement block or the else statement block

Executes case blocks until a break statement is run inti or the end of the switch statement is reached

Speed

Slower for multiple choices

Faster for multiple choices due to jump table

Editing

Difficult to edit nested if-else statements

Easier to edit switch cases

Values

Based on constraint

Based on user


The Main Difference Between If-Else and Switch

  • The difference between if-else and switch is expression within the if statement determines whether the statements inside the if block or under the else block are executed. The expression within a switch statement determines which case to execute.

  • You can have many if statements for different assertions. In the switch, there is just one expression for multiple options.

  • The if-else statement verifies equality as well as logical expression. Switch case tests for equality.

  • The difference between if-else and switch is if statement evaluates integers, characters, pointers, floating-point numbers, and booleans. A switch statement evaluates just character or numeric data types.

  • The difference between if-else and switch in c is execution sequence is as follows: either a statement from the if block or a statement from the else block will be executed. The expression in the switch statement determines which case to run, and if you do not use a break statement after each case, it will execute until the conclusion of the switch statement.

  • If the expression used inside the if block is found to be false, the statement inside the else block runs. If the expression within the switch statement is false, the default statements are directed.

Similarities Between If-Else And Switch Case Statement

Despite the difference between if-else and switch, if-else to switch case in c statements share some similarities:

1. Both are used to control the flow of program execution.

2. Both evaluate conditions to decide which block of code to execute.

3. While their syntax and representation differ, they can be used for the same purpose.

Conclusion

If-else and switch case statements are essential programming controlling statements for making decisions based on specific conditions. Understanding the difference between if-else and switch, advantages, and similarities will help you choose the right statement for your use case and make the code more efficient and readable.

FAQs

1. When should I use if-else statements instead of switch case statements?

Use if-else statements when you evaluate a condition based on various data types and expressions or when to test both equality and logical expressions.

2. When should I use switch case statements instead of if-else statements?

Use switch case statements when you evaluate a single expression for multiple choices when working with character and integer data types and when you test only equality expressions.

3. Can I use if-else statements and switch case statements interchangeably?

Both if-else and switch case statements can be used for the same purpose but have unique advantages and should be chosen based on the specific use case and your code requirements.

4. Is it possible to use if-else statements within a switch case statement or vice versa?

Yes, you can use if-else statements within a switch case statement or switch case statements within an if-else statement, based on your program's requirements.

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