How to determine the length of a one-dimensional array …

In C language, the sizeof operator can be used to obtain the length of a one-dimensional array. This operator retrieves the number of bytes occupied by an object or type. In a one-dimensional array, the length of the array can be calculated by dividing the result obtained from sizeof operator by the number of bytes occupied by a single element.

For example, for an integer array arr, you can obtain its length using the following method:

int arr[5];
int length = sizeof(arr) / sizeof(arr[0]);

In the above code, sizeof(arr) returns the total number of bytes occupied by the entire array, while sizeof(arr[0]) returns the number of bytes occupied by a single element. By dividing the two, we can obtain the length of the array. In this example, the length of array arr is 5.

It should be noted that the sizeof operator returns a value of type size_t, which represents the number of bytes. Therefore, when calculating the length of an array, it should be assigned to a corresponding integer variable.