Switch statements are used to run different blocks of code based on different conditions. They are similar to ‘If’ statements but can be a little neater when working with many conditions. This video tutorial explains how to use switch statements in JavaScript.
Switch statements look like this:
switch(expression){ case a: // code to run... break; case b: // code to run... break; default: // code to run... }
Make sure you use the break statement at the end of each case so that the program does not continue running through the switch statement once a condition has been met. If you don’t use the break statement, the program will keep checking through all conditions even if a match has already been found. If none of the conditions are met, then you can use a default case which will run another block of code.
Watch the video below and then scroll down for the sample code:
Sample HTML code:
<html> <head> <title>Switch statements</title> <script src="script.js"></script> </head> <body> </body> </html>
Sample JavaScript code (running this code would display the output “May”):
var month = 5; switch(month){ case 1: console.log("January"); break; case 2: console.log("February"); break; case 3: console.log("March"); break; case 4: console.log("April"); break; case 5: console.log("May"); break; case 6: console.log("June"); break; case 7: console.log("July"); break; case 8: console.log("August"); break; case 9: console.log("September"); break; case 10: console.log("October"); break; case 11: console.log("November"); break; case 12: console.log("December"); break; default: console.log("I'm not sure what month that is."); }
Next tutorial: While loops