Array gives error when I cross the "limit"

[blissful gust]

Idk why i am getting this error pls help

`
module main
import os {input}
fn main() {
i_max := 15
x_max := 20
mut tiles := [][]int{len:i_max, init: []int{len:x_max}}

for i:= 0; i < i_max; i+=1 {
    println("")

    for x:=0; x < x_max; x+=1 {
        if i == 0 {
            print("x")
            tiles[0][x] = 1
        }
        else if i == i_max-1 {
            print("x")
            tiles[i_max][x] = 1
        }
        else {
            if x == 0 || x == x_max-1 {
                print("x")
                tiles[i][x] = 1
            }
            else {
                print(" ")
            }
        }
    }
}
print(tiles)

}
`

this code returns error at line mut tiles := [][]int{len:i_max, init: []int{len:x_max}} cuz i cross the limit for the array

however when i edit the code to be mut tiles := [][]int{len:i_max+1, init: []int{len:x_max+1}} it doesn't give me error

what is weird; however, is the output

[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0]]

at the first array, it ends with a 0

so if it ends with a 0 then why can't i just remove the +1 from the len

here is what the code with +1 returns `

xxxxxxxxxxxxxxxxxxxx
x x
x x
x x
x x
x x
x x
x x
x x
x x
x x
x x
x x
x x
xxxxxxxxxxxxxxxxxxxx

discord f it up

bruh

here the error without +1
xV panic: array.get: index out of range (i == 15, a.len == 15) v hash: 2694624 C:/Users/AppData/Local/Temp/v_0/main.4957144200045912268.tmp.c:7984: at _v_panic: Backtrace C:/Users/AppData/Local/Temp/v_0/main.4957144200045912268.tmp.c:7236: by array_get C:/Users/AppData/Local/Temp/v_0/main.4957144200045912268.tmp.c:17895: by main__main C:/Users/AppData/Local/Temp/v_0/main.4957144200045912268.tmp.c:18288: by wmain 00494728 : by ??? 0049488b : by ??? 7ffbf86b26bd : by ???

[ornate pecan]

array indexing starts at 0

thus for a.len = 15, the last valid index is a[14]

[blissful gust]

Ye ik

[ornate pecan]

a[15] will produce an out of bounds panic

as you noticed

[blissful gust]

Where does that happen tho

[ornate pecan]

compile and run with -g

and you will get a backtrace with V's line numbers in it

[blissful gust]

It looks like same error

[ornate pecan]

for me, it shows that line 18 in your code is responsible

i.e. tiles[i_max][x] = 1

which indeed uses i_max as an index

not as a limit for the loop

[blissful gust]

OHHHH

how did I miss that

[ornate pecan]

not enough Vespene gas coffee

[blissful gust]

ok I fix with i_max-1

What is vaspene gas coffee

[ornate pecan]

it is the spice that expands consciousness for a lot of people on Earth 🙂

[blissful gust]

can I see what you got with -g

Cuz it gave me same error

[blissful gust]

oh u gotta use flag before run

[ornate pecan]

usually you can safely ignore the lines with builtin in them and concentrate on the lines from your code

yes, every flag after run is passed to your program

every flag before run is a flag that V will try to understand