《深入理解C指针》第三章 指针和函数

2019-12-01

16:42:32

 

 

 

 

 

 

 

 

 

 

#include <bits/stdc++.h>
#include <stdlib.h>
#include <stdio.h>
using namespace std;
#define maxn 10005
#define M 105
void allocateArray(int **arr,int size,int value){
    *arr = (int*)malloc(size * sizeof(int));
    printf("%p
",arr);
    if(*arr != NULL){
        for(int i=0;i<size;++i){
            *(*arr+i) = value;
        }
    }
}
int main(){
    int *vector = NULL;
    allocateArray(&vector,5,45);
    printf("%p
",vector);
    for(int i=0;i<5;++i){
        printf("%d
",vector[i]);
    }
    system("pause");
    return 0;
} 

 

 

 

 

 

 

 

 

#include <bits/stdc++.h>
#include <stdlib.h>
#include <stdio.h>
using namespace std;
#define maxn 10005
#define M 105
int (*fptrl)(int);
int square(int num){
    return num*num; 
}
int main(){
    int n = 5;
    fptrl = square;
    printf("%d squared is %d
",n,fptrl(n));
    system("pause");
    return 0;
}