If you’re ever stuck and don’t know how to solve a problem with JavaScript or just want to brush up on your skills, then you should read this guide on the JavaScript switch statement. This simple yet powerful statement allows you to change the code’s behavior based on certain conditions being met.
This article will explain everything you need to know about the switch case statement, from examples to tips and tricks. So if you’re looking for a way to solve a conditional problem quickly and easily, then read on.
Table of Contents
What is a Switch Case Statement?
A switch statement is a conditional statement that allows you to compare multiple values and execute a different action depending on which one is the correct match. This might be useful, for example, if you want to display different content based on the user’s language.
Flowchart
JavaScript Switch Case Statement : Implementation
A switch case statement is a branching structure that allows you to control code execution based on a condition. Programming often uses it to handle different scenarios and make decisions accordingly. It contains only one default clause. If there are no variables according to the given conditions, it transfers control to jump out of the loop and terminate the switch case statement.
To create a switch case statement in JavaScript, you first need to create an object containing the conditions that will be tested. This can be done using the keywords if or else, as shown below:
if (condition1) { //code } else { //code }
If the condition inside the brackets evaluates to true, then a block of code within curly braces will be executed; otherwise, it will skip over this block and go onto testing condition2. You can use multiple if statements together or combine them with other statements to build more complex decision structures.
// program using switch statement
let x = 7;
switch (x) {
case 1:
x = 'value of x is six';
break;
case 2:
x = 'value of x is seven;
break;
default:
x = 'value does not match';
break;
}
console.log(`The value of x is ${x}`); Output
Type Checking in Switch Case Statement
Type checking is a compiler construct that helps to prevent some types of errors by verifying the correctness of expressions before they are executed. This can be particularly helpful in switch case statements, where incorrect values for one of the enumerated options could lead to unexpected program behavior because they follow strict comparisons.
// program using switch statement
let x = 7;
switch (x) {
case "1":
x = 1;
break;
case 1:
x = 'one';
break;
case 2:
x = 'two';
break;
default:
x = 'not found';
break;
}
console.log(`The value of a is ${x}`); Output
Switch Case Statement Code Examples
Simple Calculator
The following simple calculator uses the switch case statement in JavaScript. Switch case statements allow you to code actions based on a specific condition. This can be helpful when you need to perform multiple tasks depending on a particular input.
For example, the switch case statement below will calculate the variable user Input as either an integer or string value. If it is an integer, the expression “number” will be evaluated and executed; if it is a string value, then “text” will be evaluated and executed instead.
const problem = "35 add 78";
const calculate = opr => {
const [num1, operation, num2] = opr.split(" ");
switch (operation) {
case "add":
console.log("addition is");
return +num1 + +num2;
case "divide":
console.log("divide is");
return +num1 / +num2;
case "subtract":
console.log("subtract is");
return +num1 - +num2;
case "multiply":
console.log("multiplication is");
return +num1 * +num2;
case "modulo":
console.log("modolus is");
return +num1 % +num2;
default:
return 0;
}
}
console.log(calculate(problem)); Output
Get the Day of Week
Using a switch case statement, you can easily determine the day of the week based on a value supplied. In this example, if the value is “Monday”, then the code will execute and return “true” (1), while if it is any other value, such as Sunday (“false”), then the code will return “false” (0).
let day = 5;
let dayName;
switch (day) {
case 1:
dayName = 'Sunday';
break;
case 2:
dayName = 'Monday';
break;
case 3:
dayName = 'Tuesday';
break;
case 4:
dayName = 'Wednesday';
break;
case 5:
dayName = 'Thursday';
break;
case 6:
dayName = 'Friday';
break;
case 7:
dayName = 'Saturday';
break;
default:
dayName = 'not valid';
}
console.log("Day is "+dayName); Output
Get the Month in a Year
In JavaScript, you can use a switch statement to count the number of days in a month. To do this, create an object that stores the days in each month and then use the switch statement to compare it to 0. If it is equal to or greater than 0, return 1; otherwise, return 0.
let year = 2022;
let month = 7;
let dayCount;
switch (month) {
case 1:
console.log("january");
break;
case 3:
console.log("march");
break;
case 5:
console.log("may");
break;
case 7:
console.log("july");
break;
case 8:
console.log("sept");
break;
case 10:
console.log("november");
break;
case 12:
console.log("december");
break;
dayCount = 31;
break;
case 4:
console.log("april");
break;
case 6:
console.log("june");
break;
case 9:
console.log("august");
break;
case 11:
console.log("october");
break;
dayCount = 30;
break;
case 2:
// for leap year
if ((year % 4 == 0 && !(year % 100 == 0)) || year % 400 == 0) {
dayCount = 29;
} else {
dayCount = 28;
}
break;
default:
dayCount = -1;
}
console.log(dayCount); Output
Switch Case vs if-else statement
- Switch statement: compares two expressions and switches between them depending on the result. For example, in this code snippet, “fruit” is compared to “apple” based on their values, and if they are equal, the condition is met, and the block of code inside curly braces will run. If the fruit has a value of “banana,” then the switch statement would not execute because banana does not compare equal to apple.
- If-else statement: when executed, it checks one condition first (in parentheses or braces that creates a block scope), and if that condition is true, it executes the associated code block; otherwise, it executes the else clause. In this example, if fruit exists but is not an apple, then Code Block A gets executed. The else clause essentially says “anything other than Apple ,” so Code Block B gets executed instead since that is what applies here.
If you are a beginner or want to learn about function, visit the article JavaScript Function.
FAQs
Can switch-case be used for all data types?
Switch-case can be used for all data types, but it might not be ideal for every situation. For example, a switch case is not appropriate if you need to easily get information from multiple objects at once.
What happens if there is no break in a switch statement?
Suppose there is no break in a switch statement. In that case, the CPU continues to run the code from the first case until the control flow either reaches the end of that case or encounters a comparison operator ( ==, >, etc.), at which point control resumes with execution proceeding from the following case.
Is switch case faster than if?
While switch case may be faster in some cases, if-else can often be more efficient regarding code readability. This is because the user does not need to remember multiple constructions (switch vs if-else), and they can instead focus on understanding the logic of the program.
Which datatype is not allowed in switch case?
The switch statement does not accept arguments of type long, float, double, boolean, or any object except for String.
Conclusion
The JavaScript switch case statement is a simple method that can solve even the trickiest problems. All you have to do is add appropriate conditions to your code and execute it based on those conditions.
With this guide, we hope that the switch statement has become much clearer. There are plenty of tips and tricks that can help you solve most cases that come up in your programming life! If you do not know where to start? Just try out some simple examples. Happy Coding.
