Table of Contents
C programming strings
In C programming, an array of characters is called a string. /0The string is terminated by the null( ) character. For example:
"c string tutorial"
Here, “c string tutorial” is string. When the compiler compiles the string, it /0appends a null( ) character to the end of the string.
C string declaration
Before working with strings, they must first be declared.
Strings are declared in the same way that arrays are declared. The only difference is the string char type.
Using array:
char s[5];
Using pointers:
char *p;
C string initialization
Strings can be initialized in different ways in C programming.
Both initialization and declaration are done in the same step for ease and convenience.
Using array:
char c[] = "abcd";
or,
char c[5] = "abcd";
or,
char c[] = {'a', 'b', 'c', 'd', '\0'};
or,
char c[5] = {'a', 'b', 'c', 'd', '\0'};
Using pointers:
Strings can also be initialized using pointers as follows:
char *c = "abcd";
Reading string from user
scanf()You can read strings using functions like any other data type .
However scanf()the function accepts only the first word of the input words. This function terminates when white space or only space is encountered.
Reading/receiving words from the user
char c[20];
scanf("%s", c);
Example: Reading string using scanf() function
//C program to better understand how to read/receive strings from terminal
#include <stdio.h>
int main()
{
char name[20];
printf("Enter your name: ");
scanf("%s", name);
printf("Your name is %s.", name);
return 0;
}
Output
Enter your name: Azizur Rahman
Your name is Azizur.
Rahman is ignored in the above program because scanf()the function accepts only one word preceding the space.
Reading a row of text
Each character is read one by one to read/receive an entire line of text.
Example: Reading a string of text using the getchar() function
// C program to better understand how to read one character at a time from the terminal
#include <stdio.h>
int main()
{
char name[30], ch;
int i = 0;
printf("Enter name: ");
while(ch != '\n') //Ends when user clicks enter button
{
ch = getchar();
name[i] = ch;
i++;
}
name[i] = '\0'; // Add the null character at the end
printf("Name: %s", name);
return 0;
}
getchar()Using the function ch in the above program takes one character from the user each time.
This process continues until the user clicks the enter button. Finally a null character is appended to the end to make it a string.
This is an annoying method for receiving strings.
Using library functions
A simpler approach to receiving and displaying strings in C programming is to use the predefined library functions gets()and respectively.puts
Example: Reading a line of text using standard library functions
//C program to read a single line of text using gets() and puts()
#include <stdio.h>
int main()
{
char name[30];
printf("Enter name: ");
get(name); //Function to read string from user
printf("Name: ");
puts(name); //String display function
return 0;
}
Both the above programs give the same output as below:
Output
Enter name: Azizur Rahman
Name: Azizur Rahman
Passing strings through functions
charStrings are similar to arrays in C programming . So they can be passed through functions in the same way as arrays.
Visit the section on passing arrays through functions to learn more .
#include <stdio.h>
void displayString(char str[]);
int main()
{
char str[50];
printf("Enter string: ");
get(str);
displayString(str); // String s is passed through the function.
return 0;
}
void displayString(char str[]){
printf("String Output: ");
puts(str);
}
In the above program, the string is spassed from main()the function to the user-defined function . displayString()Function declaration str[]is formal argument (formal argument).
C string handling functions
C programming has many types of string operations that you can perform manually. For example, determining the length of a string, copying a string, concatenation of two strings, etc.
<string.h>But many such library functions are already defined under the header file to make it easier for programmers .
Visit C programming string manipulation chapter to learn more .