Array of pointers
- C course
- Intermediate
- Lesson 2/116
- 5 min
Learn to create and use an array of pointers.
Array of pointers
An array of pointers is an array whose elements are pointers. In C the syntax int *arr[3]; declares an array of three int * elements.
Example: int a = 1, b = 2, c = 3; int *arr[3] = {&a, &b, &c};. Here arr[0] equals &a and arr[1] equals &b. *arr[1] gives you the value of b. Pointer arrays are common, especially for string lists like argv.
Pointer arrays for string lists
The most common use of pointer arrays is for string lists. In C a string is a char *; so a list of strings is held as an array of char *.
Example: char *names[3] = {"Ayşe", "Mehmet", "Zeynep"};. Each string literal lives in read-only memory; the array holds only pointers to them. names[0] gives the first string; names[1][0] gives the first letter of the second string. This structure is used everywhere from command line arguments to menu systems.
Practice Print a list of names
Declare a char *names[3] array with three names (e.g. "Ayşe", "Mehmet", "Zeynep"). Use a for loop to print each name on its own line with printf.
Starter code
#include <stdio.h>
// Declare the names array
// Loop and print each name
int main(void) {
return 0;
}Sample solution
#include <stdio.h>
int main(void) {
char *names[3] = {"Ayşe", "Mehmet", "Zeynep"};
for (int i = 0; i < 3; i++) {
printf("%s\n", names[i]);
}
return 0;
}Expected output
Ayşe Mehmet Zeynep
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Match the array of pointers parts
| Term | Meaning |
|---|---|
int *arr[3] |
Array declaration |
arr[0] |
First pointer |
*arr[1] |
Pointed value |
arr[i] = &x |
Assignment |
2 How do you declare an array of three strings?
- char **names[3];
- char names[3];
- char *names[3]; Correct answer
- char *(names);
Explanation: Char *names[3]; — three char pointers.
3 Print the second string of the array
char *names[3] = {"Ayşe", "Mehmet", "Zeynep"};
printf("%s\n", names[____]);char *names[3] = {"Ayşe", "Mehmet", "Zeynep"};
printf("%s\n", names[1]);Explanation: names[1] points to the second string "Mehmet".