I am writing C function that convert lowercase char to upper case char with using ASCII but Output is not correct

Question

Okay, So I start working on this, I have code below;

+I also have strlen("any string here") func that return len of any str in decimal just keep in your mind.

I take a lover case let's say a, then a will be equal some decimal num in ASCII table then I subtract 32 to get A.

Sadly this is not working, any idea for this? Thank you for all help and your time!

int uppercase(char sent[]) {
    
 for(int i=0; i <= strlen(sent); ++i) {
        if(sent[i]>='a' && sent[i]<='z')
            sent[i] -= 32;
}

Answer 1

This one will work:

#include <stdio.h>
#include <string.h>

void uppercase(char sent[]) {
    for (int i = 0; i < (int)strlen(sent); i++) {
        if (sent[i] >= 'a' && sent[i] <= 'z') {
            sent[i] -= 32;
        }
    }
}

int main(int argc, char* argv[]) {
    if (argc > 1){
        uppercase(argv[1]);
        puts(argv[1]);
    }

    return 0;
}

It compiles without any errors and warnings (using clang), even with options -pedantic -Wall -Wextra.