Added Ex 9,10 for If

09_if.zig

@@ -0,0 +1,31 @@
+//
+// Now we get into the fun stuff, starting with the 'if' statement!
+//
+//   if (true) {
+//      // stuff
+//   } else {
+//      // other stuff
+//   }
+//
+// Zig has the usual comparison operators such as:
+//
+//   a == b   a equals b
+//   a < b    a is less than b
+//   a !=b    a does not equal b
+//
+// The important thing about Zig's 'if' is that it *only* accepts
+// boolean values. It won't coerce numbers or other types of data
+// to true and false.
+//
+const std = @import("std");
+
+pub fn main() void {
+    const foo = 1;
+
+    if (foo) {
+        // We want out program to print this message!
+        std.debug.print("Foo is 1!\n", .{});
+    } else {
+        std.debug.print("Foo is not 1!\n", .{});
+    }
+}