A Beginner's Guide to D/Conditions and Loops/Switch Statement

Basics The switch statement can be found in almost every programming language, it's commonly used for checking multiple conditions. Syntax is identical as it is in C++ or Java. It has following form: switch(variable) { case value_to_check: statements; break; default: statements; } Here's some simple example: import std.stdio, std.string : strip; void main() { // Command that user want to launch string input; write("Enter some command: "); // Get input without whitespaces, such as newline input = strip(readln()); // We are checking input variable switch( input ) { // If input is equals to '/hello' case "/hello": writeln("Hello!"); break; // If it is equals to '/bye' case "/bye": writeln("Bye!"); break; // None of specified, unknown command default: writeln("I don't know that command"); } } And the result of our code: Enter some command: /hello Hello! Note break keyword after each case! If it's bypassed each case after it will be called. So here's console output of code without breaks: Enter some command: /hello Hello! Bye! I don't know that command As you may see, all cases after /hello were "called", this is useful if we want to call same statements in more that one case. Here's one more example: string cmd = "/hi"; switch( cmd ) { case "/hi": case "/hello": case "/wassup": writeln("Hi!"); break; // ... }