aboutsummaryrefslogtreecommitdiff
path: root/exercises/039_pointers.zig
diff options
context:
space:
mode:
authorDave Gauer <dave@ratfactor.com>2021-03-12 18:59:46 -0500
committerDave Gauer <dave@ratfactor.com>2021-03-12 18:59:46 -0500
commit6ad9774189fbd64b2f2c9519f4513ab34b0c3809 (patch)
treed6c90700131d5b28e898881f13e2a05612e4703f /exercises/039_pointers.zig
parentbe36352572ddb18218e1830e49316c259dea5e8c (diff)
downloadziglings-6ad9774189fbd64b2f2c9519f4513ab34b0c3809.tar.gz
ziglings-6ad9774189fbd64b2f2c9519f4513ab34b0c3809.tar.bz2
ziglings-6ad9774189fbd64b2f2c9519f4513ab34b0c3809.tar.xz
ziglings-6ad9774189fbd64b2f2c9519f4513ab34b0c3809.zip
"999 is enough for anybody" triple-zero padding (#18)
When I hit 999 exercises, I will finally have reached the ultimate state of soteriological release and no more exercises will be needed. The cycle will be complete. All that will be left is perfect quietude, freedom, and highest happiness.
Diffstat (limited to 'exercises/039_pointers.zig')
-rw-r--r--exercises/039_pointers.zig36
1 files changed, 36 insertions, 0 deletions
diff --git a/exercises/039_pointers.zig b/exercises/039_pointers.zig
new file mode 100644
index 0000000..d545525
--- /dev/null
+++ b/exercises/039_pointers.zig
@@ -0,0 +1,36 @@
+//
+// Check this out:
+//
+// var foo: u8 = 5; // foo is 5
+// var bar: *u8 = &foo; // bar is a pointer
+//
+// What is a pointer? It's a reference to a value. In this example
+// bar is a reference to the memory space that currently contains the
+// value 5.
+//
+// A cheatsheet given the above declarations:
+//
+// u8 the type of a u8 value
+// foo the value 5
+// *u8 the type of a pointer to a u8 value
+// &foo a reference to foo
+// bar a pointer to the value at foo
+// bar.* the value 5 (the dereferenced value "at" bar)
+//
+// We'll see why pointers are useful in a moment. For now, see if you
+// can make this example work!
+//
+const std = @import("std");
+
+pub fn main() void {
+ var num1: u8 = 5;
+ var num1_pointer: *u8 = &num1;
+
+ var num2: u8 = undefined;
+
+ // Please make num2 equal 5 using num1_pointer!
+ // (See the "cheatsheet" above for ideas.)
+ num2 = ???;
+
+ std.debug.print("num1: {}, num2: {}\n", .{ num1, num2 });
+}