How to use arrays better in C language

How to use C language arrays: First declare the creation and initialization; then use the subscript of the array to access the element content of the array, or use the C language pointer to access the array elements.

In C language, a set of data is called an array. After the creation and initialization are first declared, the element content of the array can be accessed using the subscript of the array. You can also use C language pointers to access array elements.

To put data into memory, memory space must be allocated first. To put in 4 integers, you have to allocate 4 memory spaces of type int:

Define the array int a[length]; The array is called a.

Such a set of data is called an array (Array), each data it contains is called an array element (Element), and the number of data contained is called the array length (Length) ), for example int a[4]; defines an integer array with a length of 4 and the name is a.

Each element in the array has a serial number. This serial number starts from 0, not from the familiar 1, and is called an index. When using array elements, just specify the subscript, in the form:

arrayName[index]

arrayName is the array name, and index is the subscript. For example, a[0] represents the 0th element, and a[3] represents the 3rd element.

Creation and initialization of arrays

#include<stdio.h>
int main()
{
    char arr1[] = { &#39;a&#39;, &#39;b&#39;, &#39;c&#39; };
    char arr2[3] = "abc";
    char *p = "abc";//这里只是把a的地址放进了p里边
    return 0; 
}

##Simple use of arrays

#include<stdio.h>
int main()
{
    int arr[10] = { 0 };
    int i = 0;
    for (i = 0; i < 10; i++)//i<11是不可以的，不可以越界访问
    {
        arr[i] = i;
    }
    return 0; 
}

Arrays are accessed using subscripts, which start from 0.

The size of the array can be calculated. (sz = sizeof(arr)/sizeof(arr[0]));

Pointer access to the array uses

int main()
{
    int arr[10] = { 0 };
    int i = 0;
    int sz = sizeof(arr) / sizeof(arr[0]);
    int *p = arr;
    for (i = 0; i < sz; i++)
    {
        //arr[i] = i; (1)
        *(p + i) = i; (2)
    }
    for (i = 0; i < sz; i++)
    {
        printf("%d\n", arr[i]);//(1)和(2)的输出结果一样
    }
    return 0; 
}

From the output results, we can see that we A pointer p is defined, pointing to arr, and then we access the array through the pointer.

The above is the detailed content of How to use arrays better in C language. For more information, please follow other related articles on the PHP Chinese website!