C Strings

In this tutorial, we will learn about strings their declaration and initialization in C programming with the help of examples.

Strings

String is an one-dimesional array of char type terminated by a null character \0 .

Syntax

char array_name[] = "character_array elements";

Declaring String

char array_name[array_size];

Example

char name[10];

Initializing String

Different ways to initialize strings in C programming -

char name[] = "Albert";
char name[50] = "Albert";
char name[] = {'A', 'l', 'b', 'e',  'r', 't','\0'};
char name[5] = {'A', 'l', 'b', 'e', 'r', 't', '\0'};

Common Mistakes while initializing strings

char name[6] = "Albert";

Here, we are trying to assign 7 characters in which Albert has 6 character and the last or 7th character is null character \0 in array name of char type. But we have initialize the size of array as 6 but we are trying to assign 7 characters. So, this condition will provide us with an error.

Assigning Values to Strings

In C programming, Arrays and Strings do not support the assignment operator once they declared.

Example : Assigning values to strings

char name[50];
name = "Albert";  // Error

Intead of using assignments operators, we can use strcpy() function to copy the string.

Note: Use the strcpy() function is used to copy one string to another.

Read Values from the user

We can use the scanf() to function to read a string value from the user.

The scanf() function can only read the sequence of characters until it encounters a whitespace (tab, newline, etc).

Example : scanf() to read a string

#include <stdio.h>
int main() {
  char name[10];
  printf("Enter your name : ");
  scanf("%s", &name);
  printf("Your name is %s.", name);
  return 0;
}

Output

Enter your name : Nikola Tesla
Your name is Nikola.

In the above example, The variable name is only printed until a whitespace encounters.

In C programming, we are provided with a format specifier %s for string.

Note : It is not necessary to use ampersand & sign while taking a string input in scanf() function.

fgets() & puts() : Read and print a line of Text

We are provided with fgets() and puts() functions to read a line of string and to display the string respecitvely.

Example : fgets() and puts()

#include <stdio.h>
int main() {
  char name[20];
  printf("Enter your name: ");
  fgets(name, sizeof(name), stdin);  // read string
  printf("Hello ");
  puts(name);  // display string
  return 0;
}

Output

Enter your name: Carl Johnson
Hello Carl Johnson

Here, we have used fgets() function to read a string from the user and puts() to printstring.

In fgets() and puts() functions it is not required to use format specifiers.

Passing Strings to Functions

#include <stdio.h>
void displayString(char name[]) {
  printf("Output : ");
  puts(name);
}
int main() {
  char name[50];
  printf("Enter something about yourself : ");
  fgets(name, sizeof(name), stdin);
  // Passing string to a function
  displayString(name);
  return 0;
}

Output

Enter something about yourself : My name is Tony Stark.
Output : My name is Tony Stark.

Pointers and Strings

#include <stdio.h>
int main(void) {
char favMovie[] = "Avengers";
  printf("%c", *favMovie);  // Print staring character of array
  printf("%c", *(favMovie+1));  // Print first Character after array starting character 
  printf("%c", *(favMovie+3));  // Print third Character after array starting character
  char *moviePtr;
  moviePtr = favMovie;
  printf("%c", *moviePtr);
  printf("%c", *(moviePtr+1));
  printf("%c", *(moviePtr+7));
}

Output

A
v
n
A
v
s

Here, we have used %c to print the characters from the character array favMovie[].

Next Tutorial

We hope that this tutorial helped you develop better understanding of the concept of Strings in C.

Keep Learning : )

In the next tutorial, you'll learn about C String Functions.