Difference Between If-Else and Switch
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Overview
In our day-to-day lives, we make several decisions, from deciding what to wear to deciding what to eat. Sometimes your actions depend on your decisions. For example, if you have already brushed your teeth, you can eat, else you will have to brush your teeth first. In coding, we use conditional statements for this purpose. Conditional Statements are if, else, else-if and switch. While starting with coding, if-else and switch are one of the first things that you learn. It is hence important to understand the benefits and differences between each. This is what we will cover in this article.
What is an If-Else Statement?
In our day-to-day lives, we always decide on things by using if-else. For example, let's consider a situation where we need to think about the number of days present in each month. If the month is either of January, March, May, July, August, October, and December, the answer is 31. If the month is either April, June, September, and November, the answer is 30. If the month is a leap year, February, the answer is 29. If not a leap year February, the answer is 28. The if-else statement allows the programmer to do exactly that with their code. A condition check is done. If it is true, control goes to one block of code, and if it isn’t, then control goes to a different block of code defined in else. The else statement can either be a single statement, or it can even be a block of statements.
Syntax of if-else statement
Example of if-else statement
What is a Switch Statement?
In the switch statement, we compare the condition value with multiple cases. When there is a match with any one of the cases, the block of code corresponding with that case is executed. Each case has a name or a number, which is known as its identifier. If none of the cases matches the condition, the block of code corresponding to the default case is executed. The same example of finding number of days in each month is done using the switch below.
Syntax of the switch statement
Example of Switch Statement
Explanation
In switch, if we don't have a break statement, a matching case falls through until it encounters a break statement, which will be printed with the exception of the default case. In the above code, month 1 means January, month 2 means February, and so on. We know that January, March, May, July, August, October, and December have 31 days, while April, June, September, and November have 30 days. So, instead of adding a print statement after each of these, we can have it only for one of them and add a break statement after that. Let's consider the case when we want to find the number of days in the 9th month or September. We go through the code till we find case 9. After that, we go to case 11, encounter a print statement, and print 30. Then we break out of the switch case.
Some Key Advantages of Switch over If-Else Ladder
- A switch statement is significantly faster than an if-else ladder if there are many nested if-else's involved. This is due to the creation of a jump table for switch during compilation. As a result, instead of checking which case is satisfied throughout execution, it just decides which case must be completed. The number of comparisons made is lesser hence, reducing the compile time. Hence, the switch would work better while selecting from a large set of values.
- When compared to if-else statements, it is more readable. You can also see this in the examples given above. In the if-else code, you can't clearly see the months which have 30 days; however, in switch, it's easily highlighted.
Difference Between If-Else and Switch Statement
| Parameter | If-Else | Switch |
|---|---|---|
| Definition | The if and else blocks are executed depending on the condition in the if statement | The switch statement has multiple cases, and the code block corresponding to that case is executed |
| Evaluation | Used for integer, character, pointer, floating-point type, 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 | If the condition inside the if-statement is false, then the code block under the else condition is executed | If the condition inside switch statements does not match any of the cases, the default statement is executed. |
| Sequence of Execution | Either the code block in the if statement is executed or the code block in the else statement. | The switch case statement performs each case until a break statement is encountered or the end of the switch statement is reached. |
| Speed | If you use 'if-else' to implement several options, the speed will be slow. | If we have numerous options, the switch statement is the best solution because it executes considerably faster than the 'if-else' statement. |
| Editing | Difficult to edit nested if-else statements. | Easy to edit. |
| Values | Based on constraint | Based on user |
Main Difference Between If-Else and Switch Case
The main differences between the two are:
- The if-else statement is used to choose between two options, but the switch case statement is used to choose between numerous options.
- If the condition inside the if block is false, the statement inside the else block is executed. If the condition inside the switch statement is false, the default statements are run.
- If-else values are determined by constraints, whereas switch case values are determined by user preferences.
- It's difficult to make changes to if-else statements because it's time-consuming to figure out where the change needs to be made. Switch statements, on the other hand, are simple to change since they are easy to trace.
- For numerous statements, you can use several if statements. For numerous statements in Switch, you only have one expression.
Some Of The Similarities Between If-Else And Switch Case Statement
Now that we have seen and understood the differences between if-else and switch, it is time to see the similarities between the two. These are:
- They are both employed to control the flow of execution of the program
- They both evaluate a condition, and then the flow of the program depends on that
- Their syntax and way of representation differ but can be used for the same purpose
Conclusion
In this article, we have summed up the main differences and similarities between if-else and switch. These are both very commonly used conditional statements, and to wrap it all up:
- It is up to the user if they would like to use if else or switch as they both serve the same purpose.
- Both if-else and switch have their own set of advantages over one another.
- It is ideal to use if else when checking if a condition is true or false.
- It is ideal to use a switch instead of using nested if-else statements as it is faster due to the creation of a jump table.