test:zig

guide/language/functions.zig

@@ -0,0 +1,30 @@
+const expect = @import("std").testing.expect;
+
+fn addFive(x: u32) u32 {
+    return x + 5;
+}
+
+test "function" {
+    const y = addFive(0);
+    try expect(@TypeOf(y) == u32);
+    try expect(y == 5);
+}
+
+fn fibonacci(n: u16) u16 {
+    if (n == 0 or n == 1) return n;
+    return fibonacci(n - 1) + fibonacci(n - 2);
+}
+
+test "function recursion" {
+    const x = fibonacci(10);
+    try expect(x == 55);
+}
+
+// When recursion happens, the compiler is no longer able to work out the maximum stack size,
+// which may result in unsafe behaviour - a stack overflow.
+// Details on how to achieve safe recursion will be covered in the future.
+//
+// Values can be ignored using _ instead of a variable or const declaration.
+// This does not work at the global scope (i.e. it only works inside functions and blocks)
+// and is useful for ignoring the values returned from functions if you do not need them.
+// _ = 10; // ignore the value 10