Beginner's Guide to Zig Part 2 - Slices, Printing, If statements and loops

[@pietraderdetective8953]

Love the Zig content! I particularly love how C and Zig are 1:1.

[@ericmisha]

(assuming a,b,c,d are booleans for the sake of simplicity)
Instead of:
if (a || b)
use:
if (a or b)
Instead of:
if (a && b)
use:
if (a and b)
You can also combined them as you'd expect, for example:
if ((a and b) or (c and d))

[@zigzig-b9p]

Hi
Thanks for this video. I have a few comments. If I have got the wrong end of the stick please advise.
zig does not infer types like basic or python.
const my_const=10; is syntax sugar for const my_const:comptime_int=10;
You see a const is a comptime variable. The reason it does not do that for a var is because a var can exist in runtime and therefore needs a type.
If however you tell the compiler that var is comptime it works fine. See below
const std = @import("std"); // this loads the standard library for zig
pub fn main() !void {
//const my_const:comptime_int=10; // syntax sugar below
const my_const=10; // this is a comptime variable; Therefore it becomes a comptime_int
//
// var my_var=10; // Error: variable of type 'comptime_int' must be const or comptime
comptime var my_var=10; // because we have told the compiler that var is comptime it becomes a comptime_int
// show me the type
std.debug.print("my_const type = {any}
", .{@TypeOf(my_const) } );
std.debug.print("my_var type = {any}
", .{@TypeOf(my_var) } );
// tidy up so that the code compiles
//_=my_const; // need to give const home
my_var+=1; // need to mutate var
} // end of main
You mentioned slices.
const std = @import("std"); // this loads the standard library for zig
pub fn main() !void {
// the const not_slice is a single pointer, to a read only part of ram ie *const [11:0]u8
// The read only ram is an array [0]=H, [1]=e, [2]=l etc
// It's null terminated ie :0. It has a length of 11
const not_slice="Hello world";
std.debug.print("Not_slice type = {any}, it_contains {s}
", .{@TypeOf(not_slice), not_slice} ); //
// slice is defined as a fat pointer ie []const u8. The const here means read only ram
//const slice:[] const u8 = not_slice[0..4];
const slice:[] const u8 = not_slice; // this would be the same as [0..]
std.debug.print("Slice type = {any}, it_contains {s}
", .{@TypeOf(slice), slice} ); //
// Lets print a chracter ie {c}
std.debug.print( "{c}
", .{not_slice[0]} ); //
std.debug.print( "{c}
", .{not_slice[1]} ); //
// lets print a string, which is not a slice
std.debug.print( "{s}
", .{not_slice} ); //
}
Hopefully this is all correct.

[@CodingWithTom-tn7nl]

You're correct about constant variables and inferring.
On slices, maybe there is a semantic difference but I believe they are basically the same:
const string1:*const [11:0]u8 = "Hello world";
const string2:*const [11]u8 = "Hello world";
const string3:[]const u8 = "Hello world";
std.debug.print("{} {} {}
", .{@TypeOf(string1), @TypeOf(string2), @TypeOf(string3)});
std.debug.print("{s} {s} {s}
",.{string1, string2, string3});
std.debug.print("{c} {c} {c}
",.{string1[0], string2[0], string3[0]});
const length1 = string1.len;
const length2 = string2.len;
const length3 = string2.len;
std.debug.print("{} {} {}
",.{length1, length2, length3});
You print these both with {s} which shows they are both slices. In string1 and string2 you simply specify the length.
You can even write it without the ":0" and it still does the same thing.

[@TheFreshMakerHD]

7:00 to print a slice of numbers (decimal, int, etc) is to use {d} in the formatter ex: std.debug.print("{d}", .{number_slice});

[@CodingWithTom-tn7nl]

Thanks, I wasn't aware of that

[@nikolazivkovic9541]

13:10 you could have used keyword 'and' instead of &&

[@CodingWithTom-tn7nl]

I wasn't aware of that keyword when I made the video, I didn't find it mentioned anywhere in any guides. I only recently found 'and' and 'or' randomly in a function in the standard library. I'll probably make a future video including those.

[@dabunnisher29]

Sorry to say this but the speed that you swing up and down makes it hard for viewers like me see what you are talking about.

[@CodingWithTom-tn7nl]

Sorry about that, soon I'll make all the code available in a github page so people can look themselves if they like