Difference Between if else and switch

The main difference between if else and switch is that, in if else, the block to execute depends on the expression in if statement while, in switch, the execution depends on the single variable passed to it.

There are various decision-making structures in programming. Two of them are if else and switch. In if else, there are two blocks as if and else. The “if” block consists of an expression. If the expression is true, the statements inside the “if” block will execute. If the expression is false, the statements inside the else block will execute. On the other hand, switch consists of multiple case statements. It receives a single variable. Deciding which case block to execute depends on the variable passed to it.

Key Areas Covered

1. What is if else
     – Definition, Functionality
2. What is switch
     – Definition, Functionality
3. Difference Between if else and switch
     – Comparison of Key Differences

Key Terms

if else, switch, programming

What is if else

If else is a mechanism to accomplish decision making in programming. It consists of two blocks: if block and the else block. If block contains the expression to evaluate. If that expression is true, the statements inside if block will be executed. If the expression is false, the statements inside the else block will be executed. Refer the below program.

Figure 1: Program with if else

According to the above program, the marks variable contains the value 60. In if block, the expression is checked. It checks whether the value of marks is equal or greater than 75. The actual value of marks is 60, so the expression is false. Therefore, the statement inside if block will not be executed. Instead, the statement inside the else block will be executed.

What is switch

Switch checks the value of a single variable. It has multiple case statements. Depending on the variable passed to the switch, it checks each case statement’s value. When the case value matches with the received value, the statements inside that particular case will be executed.

When the break occurs, the control goes out of the switch to the very next statement after the switch. If a case does not have a break, the execution will pass to the next case and so on. Finally, the default will be executed if none of the case is true. It does not require a break. Refer the below program.

Figure 2: Program with switch

According to the above program, the grade contains a character. This grade is passed to the switch. Then, all the case statements are checked. The passed character is ‘B’. Therefore, the corresponding statement in case ‘B’: will be executed. When the break occurs, the control goes out of the switch and passes to the first line after the switch.

Difference Between if else and switch

Definition

if else is a control structure that executes statements if the condition is true and executes the option block if the condition is false while switch is a section control mechanism that allows a value or a variable to change the control flow of the program execution via a multi-way branch.

Execution

That is, if the expression in the “if” block is true, the statements inside the “if” block will execute. If not, the else block will execute. The execution block depends on the evaluated expression. The switch executes the statements in the matched case until a break statement.

Default Execution

Furthermore, if the condition in the “if” block is false, the else will execute. In switch, if there is no matching case statement, the control will pass to the first line after the switch.

Testing

Moreover, if else checks the equality and logical expressions while switch checks the equality.

Conclusion

if else and switch are two decision making structures in programming. The difference between if else and switch is that, in if else, the block to execute depends on the expression in if statement while in switch, the execution depends on the single variable passed to it.

Reference:

1. “If…else Statement in C.” Www.tutorialspoint.com, Tutorials Point, 12 Aug. 2018, Available here.
2.“Switch Statement in C.” Www.tutorialspoint.com, Tutorials Point, 12 Aug. 2018, Available here.