Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

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

int parse_int(const char *str, int *out)
{
    char *end;
    errno = 0;
    long val = strtol(str, &end, 10);
    if (errno != 0 || end == str || *end != '\0') return -1;
    *out = (int)val;
    return 0;
}

int main(void)
{
    /* snprintf: safe formatted string building */
    char buf[128];
    int  n = snprintf(buf, sizeof(buf),
                      "User: %-10s Age: %3d Score: %.2f",
                      "Alice", 30, 98.756);
    printf("snprintf wrote %d chars: \"%s\"
", n, buf);

/* sscanf: parsing a structured line */
    const char *line = "Bob 25 87.5";
    char   name[32];
    int    age;
    double score;
    int    parsed = sscanf(line, "%31s %d %lf", name, &age, &score);
    if (parsed == 3)
        printf("Parsed: name=%s age=%d score=%.1f
", name, age, score);

/* strtol: safe string-to-int with error detection */
    int value;
    const char *inputs[] = { "42", "  -17", "3.14", "99abc", "xyz" };
    for (int i = 0; i < 5; i++) {
        if (parse_int(inputs[i], &value) == 0)
            printf("'%s' -> %d
",   inputs[i], value);
        else
            printf("'%s' -> parse error
", inputs[i]);
    }

return 0;
}