As I learned JavaScript, I often found myself stuck between using switch or if-else statements. It's a common dilemma for beginners. Let's dive into these two choices together, exploring what they offer and when to use each one.
Readability: For simple cases where you're testing the value of a single variable against multiple conditions, switch statements can often be more readable and maintainable. They provide a clear structure for handling multiple cases.
switch (day) {
case 'Monday':
case 'Tuesday':
case 'Wednesday':
case 'Thursday':
case 'Friday':
console.log('Weekday');
break;
case 'Saturday':
case 'Sunday':
console.log('Weekend');
break;
default:
console.log('Invalid day');
}
Performance: In JavaScript, the performance difference between switch and if-else statements is generally negligible. Modern JavaScript engines are quite efficient in optimizing both constructs.
Flexibility: if-else statements provide more flexibility for complex conditional logic. You can use logical operators and test multiple conditions within a single if or else if block, which can sometimes be more concise and expressive.
if (score >= 90) {
console.log('A');
} else if (score >= 80) {
console.log('B');
} else if (score >= 70) {
console.log('C');
} else {
console.log('D');
}
Handling Different Types of Conditions: if-else statements are more versatile when dealing with conditions beyond simple value comparisons, such as ranges or boolean expressions.
if (age < 18) {
console.log('Minor');
} else if (age >= 18 && age < 65) {
console.log('Adult');
} else {
console.log('Senior');
}
Here’s the general layout of an if-else statement verses the switch case:
This is the general syntax of an if-else statement:
if (condition1) { //Body of if }
else if (condition2) { //Body of if }
else if (condition3) { //Body of if }
else { //default if all conditions return false }
And this is the general syntax for switch:
switch ( variable )
{
case <variable value1>: //Do Something
break;
case <variable value2>://Do Something
break;
default: //Default will perform if all case’s fail
break;
}
The if-else ladder is of type strict condition check, while switch is of type jump value catching.
Some key advantages of switch over if-else ladder:
A switch statement works much faster than an equivalent if-else ladder. It’s because the compiler generates a jump table for a switch during compilation. As a result, during execution, instead of checking which case is satisfied, it only decides which case has to be executed.
It’s more readable compared to if-else statements.
In the end, the choice is yours and I hope this blog helps lead you in the right path to making the most informed decision when to use an if-else statement verses a switch case!
Top comments (1)
Something that caught me by surprise is that variable scope is shared across all cases in a switch statement. This is not the case with if-else. For example if const foo = 'bar' is defined in the first switch case, const foo = 'cherry' is not valid in the second case. Using if-else, this would work as expected and the constant foo could be set in each if block because each block has its own scope.