C语言函数参数 #

int add(int a, int b) {
    return a + b;
}

int main() {
    add(1, 2);
    return 0;
}

#include <stdio.h>

void modify(int a) {
    a = 100;
    printf("函数内: %d\n", a);
}

int main() {
    int x = 10;
    modify(x);
    printf("函数外: %d\n", x);
    return 0;
}

函数内: 100
函数外: 10

#include <stdio.h>

void modify(int* a) {
    *a = 100;
}

int main() {
    int x = 10;
    modify(&x);
    printf("x = %d\n", x);
    return 0;
}

#include <stdio.h>

void swap(int* a, int* b) {
    int temp = *a;
    *a = *b;
    *b = temp;
}

int main() {
    int x = 10, y = 20;
    swap(&x, &y);
    printf("x=%d, y=%d\n", x, y);
    return 0;
}

#include <stdio.h>

int sum(int arr[], int size) {
    int total = 0;
    for (int i = 0; i < size; i++) {
        total += arr[i];
    }
    return total;
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    printf("总和: %d\n", sum(arr, 5));
    return 0;
}

#include <stdio.h>

void print_string(const char* str) {
    printf("%s\n", str);
}