Conditional statements

A conditional statement ( if (expr) { ... } elif (expr) {} else { ... };) allows you to evaluate complex decision trees. Starting with version 4.10, you can also use switch-case expressions.

Switch-case expressions allow you to better organize the code instead of using multiple if, elif, else blocks. Using switch-case expressions also improves performance.

Usage:

  switch (<expression-or-variable>) {
    case "literal-string1":
      ...
      break;
    case "literal-string2":
      ...
      break;
    case <expression>:
      ...
      break;
    default:
      ...
      break;
};

For example:

  switch ($MESSAGE) {
    case "foobar":
      $MESSAGE = "literal-case";
      break;
    case any_expression:
      $MESSAGE = "variable-case";
      break;
    default:
      $MESSAGE = "default";
      break;
};

Note that:

• Cases with literal string targets are stored in a map, and the lookup is started with them.
• Case targets can contain any expressions, and they are evaluated in order.
• Literal string and default target duplications are checked and will cause init failure. Non-literal expression targets are not checked, and only the first matching case will be executed.