[C++] 5 traversal methods for character arrays

In C++, how to traverse the following character array:

char str[] = {
    
    'z','i','f','u', 's', 'h', 'u', 'z', 'u'};

1. Array + subscript

Note that this method uses the strlen function and must introduce the cstring standard library:

#include <cstring>

for (int i = 0; i < strlen(str); i++)
{
    
    
    cout << str[i] << ' ';
}

2. Pointer + while

This method takes advantage of the fact that character arrays end with "\0":

char *p = str;
while (*p != '\0')
{
    
    
    cout << *p << " ";
    p++;
}

3. Pointer + for

To calculate the number of times a pointer needs to be incremented based on strlen, you also need to use the cstring standard library:

#include <cstring>

char *p2 = str;
for (int i = 0; i < strlen(str); i++)
{
    
    
    cout << *p2 << " ";
    p2++;
}

4. Pointer + subscript

Using the cstring standard library and comparing method 1, the pointer can be regarded as equivalent to the array name:

char *p3 = str;
for (int i = 0; i < strlen(str); i++)
{
    
    
    cout << p3[i] << " ";
}

五、nullptr + while

Stop when the traversal reaches the null pointer. This method is similar to method 2:

// 方法五：nullptr + while
char *p4 = str;
while (p4 != nullptr)
{
    
    
    cout << *p4 << " ";
    p4++;
}

Running screenshot:

Appendix: Complete code

#include <iostream>
#include <cstring>

using namespace std;

int main()
{
    
    
    char str[] = {
    
    'z', 'i', 'f', 'u', 's', 'h', 'u', 'z', 'u'};

    // 方法一：数组 + 下标
    cout << "method1:";
    for (int i = 0; i < strlen(str); i++)
    {
    
    
        cout << str[i] << ' ';
    }

    // 方法二：指针 + while
    cout << endl
         << "method2:";
    char *p1 = str;
    while (*p1 != '\0')
    {
    
    
        cout << *p1 << " ";
        p1++;
    }

    // 方法三：指针 + for
    cout << endl
         << "method3:";
    char *p2 = str;
    for (int i = 0; i < strlen(str); i++)
    {
    
    
        cout << *p2 << " ";
        p2++;
    }

    // 方法四：指针 + 下标
    cout << endl
         << "method4:";
    char *p3 = str;
    for (int i = 0; i < strlen(str); i++)
    {
    
    
        cout << p3[i] << " ";
    }
    
	// 方法五：nullptr + while
	cout << endl
	     << "method5:";
	char *p4 = str;
	while (p4 != nullptr)
	{
    
    
	    cout << *p4 << " ";
	    p4++;
	}

    return 0;
}