Javascript | Switch statements

JavaScript switch statements are a type of conditional statement that is often used when you need to execute different blocks of code based on different values of a variable. In this article, we will explore the use of switch statements in JavaScript, with examples to illustrate their syntax and usage.

Syntax: The syntax for a switch statement in JavaScript is as follows:

switch (expression) {
  case value1:
    // code to execute when expression matches value1
    break;
  case value2:
    // code to execute when expression matches value2
    break;
  ...
  default:
    // code to execute when expression does not match any of the cases
    break;
}

The switch statement begins with the keyword “switch”, followed by the expression that you want to evaluate. This expression is compared to each of the case values, one by one. When the expression matches a case value, the code inside that case is executed. The “break” statement is used to exit the switch statement and continue executing the rest of the code.

If the expression does not match any of the case values, the code inside the “default” block is executed.

Example: Let’s take a look at a simple example to understand the switch statement in action:

let day = new Date().getDay();
let dayStr;

switch(day) {
  case 0:
    dayStr = "Sunday";
    break;
  case 1:
    dayStr = "Monday";
    break;
  case 2:
    dayStr = "Tuesday";
    break;
  case 3:
    dayStr = "Wednesday";
    break;
  case 4:
    dayStr = "Thursday";
    break;
  case 5:
    dayStr = "Friday";
    break;
  case 6:
    dayStr = "Saturday";
    break;
  default:
    dayStr = "Invalid day";
    break;
}

console.log("Today is " + dayStr);

In this example, we first get the current day of the week using the getDay() method. We then use a switch statement to assign a string value to the dayStr variable, based on the day of the week. If the day is not a valid value, the default case is executed.

Switch statements are particularly useful when you have a large number of possible values for a variable. In such cases, using multiple if-else statements can become cumbersome and inefficient. Switch statements provide a cleaner and more concise way of handling such scenarios.

In conclusion, switch statements are a powerful tool in the JavaScript programmer’s arsenal, and can help you write code that is more efficient and easy to read. By understanding the syntax and usage of switch statements, you can take your JavaScript programming skills to the next level.