C语言字符串操作 #

#include <stdio.h>
#include <stdlib.h>

int main() {
    printf("%d\n", atoi("123"));
    printf("%ld\n", atol("123456"));
    printf("%f\n", atof("3.14"));
    return 0;
}

#include <stdio.h>

int main() {
    char buf[20];
    sprintf(buf, "%d", 123);
    printf("字符串: %s\n", buf);
    return 0;
}

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

int main() {
    char str[] = "Hello,World,C";
    char* token = strtok(str, ",");
    
    while (token != NULL) {
        printf("%s\n", token);
        token = strtok(NULL, ",");
    }
    return 0;
}

#include <stdio.h>

int main() {
    char buf[100];
    int a = 10, b = 20;
    sprintf(buf, "%d + %d = %d", a, b, a + b);
    printf("%s\n", buf);
    return 0;
}

#include <stdio.h>

int main() {
    char str[] = "10 20 30";
    int a, b, c;
    sscanf(str, "%d %d %d", &a, &b, &c);
    printf("%d, %d, %d\n", a, b, c);
    return 0;
}

#include <stdio.h>
#include <ctype.h>

int main() {
    char c = 'a';
    printf("大写: %c\n", toupper(c));
    printf("小写: %c\n", tolower('A'));
    return 0;
}