There are decision making structures in programming. The if else and switch are two of them. An expression consists of values, operators, constants etc. The if else allows executing a block of statements if the given expression is true or to execute the optional block if the given expression is false. The switch is used to allow the value of a variable or expression to change the control flow of program execution via a multiway branch. If the programmer wants to check the value of a single variable, then he can use switch statement. This article discusses the difference between if else and switch. The key difference between if else and switch is that in if else, the execution block is based on the evaluation of the expression in if statement, while in switch, the statements to execute depend on the single variable passed to it.
CONTENTS
1. Overview and Key Difference
2. What is if else
3. What is switch
4. Similarities Between if else and switch
5. Side by Side Comparison – if else vs switch in Tabular Form
6. Summary
What is if else?
If else contains two blocks. They are if and else. The if block contains the expression to evaluate. If it is true, the statements inside the if block will execute. If the condition is false, then the statements belong to else block will execute. Programming languages assume any non-zero and non-null values as true. The zero and null are considered as false. The if and else are keywords. Therefore, they cannot be used as identifiers.
Figure 01: Program with if else Statements
According to the above program, the number is variable that can store integers. It contains value 5. In the if block, the expression is checked. If the remainder is 0 after dividing the number by zero, which means the number is even. If the remainder is 1, then the number is odd. Number 5 is odd. Therefore, the else block will execute.
What is switch?
If the programmer wants to check on the value of a single variable, then he can use the switch. It is a multiple-choice selection statement. The switch can have many case statements. When the variable is passed to the switch, it is compared with each case statement’s value. If the corresponding value found, the statements of that particular case execute. Those statements execute till a break occurs. If case statements do not have break statements, then the execution happens until the end of the switch statement. The default case executes if none of the cases is true. The default does not require a break statement.
Figure 02: Program with switch
According to the above program, the num1 and num2 contain two integer values. The operator is a character. It is passed to the switch. It is checked with all case statements. The passed operator is division. Therefore, the division is calculated and printed. Then the execution goes out of the switch because of the break statement. When the break is reached, the control is passed to the next line after the switch. Generally, the switch statement often uses a keyboard command to choose one among the multiple case statements.
What is the Similarity Between if else and switch?
- Both if else and switch are decision making structures in programming.
What is the Difference Between if else and switch?
if else vs switch |
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| The if else is a control structure that executes a block of statements if the condition is true and executes the optional block if the condition is false. | The switch statement is a type of selection control mechanism used to allow the value of a variable or expression to change the control flow of program execution via a multiway branch. |
| Execution | |
| In if else, either the if block or the else block executes depending on the evaluated expression. | The switch executes one case after the other until the break is reached or until the end of the switch. |
| Evaluation | |
| The if statement evaluates, integers, characters, floating point numbers or Boolean types. | The switch statement evaluates characters and integers. |
| Default Execution | |
| If the condition of if block is false, the statements inside the else block will execute. | In switch, if none of the case statements match, the default statements will execute. |
| Testing | |
| The if else check the equality and logical expressions. | The switch checks the equality. |
Summary – if else vs switch
Two decision making structures in programming are if else and switch. The if else statement is a conditional statement will run a set of statements depending on whether the condition is true or false. The switch can be used check a single variable. The difference between if else and switch is that if else the execution block based on the evaluation of the expression in if statement, while the switch statement selects the statements to execute depending on the single variable, passed to it.
Reference:
1.“Switch statement.” Wikipedia, Wikimedia Foundation, 28 Feb. 2018. Available here
2.Point, Tutorials. “If…else statement in C.”, Tutorials Point, 8 Jan. 2018. Available here
3.Point, Tutorials. “Switch statement in C.”, Tutorials Point, 8 Jan. 2018. Available here