36. Control Flow: The switch Statement

The switch statement is an alternative to long if...else if chains when you are comparing a single expression against multiple possible constant values.

Syntax

javascript switch (expression) { case value1: // Code if expression === value1 break; case value2: // Code if expression === value2 break; default: // Code if no match is found }

Example: Day of the Week

javascript let day = 'Wednesday'; let type;

switch (day) { case 'Saturday': case 'Sunday': type = 'Weekend'; break; case 'Wednesday': type = 'Mid-Week'; break; default: type = 'Weekday'; }

console.log(day + ' is a ' + type); // Output: Wednesday is a Mid-Week

The Crucial break Keyword

If you omit break, the execution will 'fall through' to the next case, regardless of whether it matches. This is rarely desired and is the most common beginner mistake with switch statements.