C Tutorial

C Tutorial C Language Environment Setup Execution flow of C program C printf and Scanf C Data type C Token Variable in C Operators in C Comments in C Escape Sequence in C C – Storage Classes C Decision control statement Loop Statement in C Break, continue and goto statement in C Type Casting in C Function in C Recursion in C String in C C Array Pointer in C Dynamic memory allocation C –Structure Nested Structure in C Union in C File Handling in C C pre-processor Static Function In C Sizeof In C Selection Sort In C Scope Of Variables In C Runtime Vs Compile Time In C Random Access Lseek In C Queue Implementation In C Pseudo Code In C Prototype In C Pointer To Pointer In C Pointer Arithmetic In C Passing Array To Function In C Null Character In C Merge Sort In C Macros In C Library Functions In C Memory Leak In C Int In C Goto And Labels In C Fibonacci Series In C Fflush In C Derived Data Types In C Data Types In C Const Vs Volatile In C Character Set In C Character Class Tests In C Calloc In C C Pointers Arrays In C Include In C Clrscr In C C Vs Java String Literals In C Types Of Pointers In C Variables In C Volatile In C Why C Is A Middle Level Language Infix To Postfix Program In C Ceil function in C LCM of two numbers in C Quick sort in C Static in C function pointer as argument in C Top Array Keywords in C Add two numbers using the function in C Armstrong program in C using function Array, Declaring Arrays and Array Initialization Limitations of Inline Function in C Merge and Merge sort with example in C Do-While Loop in C For Loop in C While-Loop in C Difference between while and do-while loop in C Array Of Structures in C Data Structures And Algorithms in C Types Of Structures In C How to Avoid Structure Padding in C Use of Structure in C Do WHILE LOOP in C Programming Examples For Loop in C Programming Examples Entry Control Loop in C Exit control loop in C Infinite loop in C Nested loop in C pow() function in C String Handling functions in C Prime Number code in C Factorial Program in C using For Loop Factorial Program in C Using While Loop Fibonacci Series in C Using For Loop Fibonacci series in C using while loop Prime Number Program in C using for Loop While Loop in C programming examples Built-in functions in C Assert() Function C vs Java Strings Call Back Function in Embedded C Else If Ladder fgets() function Ftell() Function getc() function getch() function gets() function Heap Sort Nested if-else statement Pi() Function Positioning of file Write() function abs() function in C Attributes in C C program to find factorial of a number using Recursion Ferror() in c fopen() function in C Fibonacci series program in C using Recursion Formatted Input and output function in C Snake Game in C User Defined Functions in C Beep() function in C Cbrt() function in C Hook() function in C Isalnum() function in C C Program to find the Roots of a Quadratic Equation C Switch Statements Difference between rand() and srand() function in C Difference between while and for loop in C Doubly Linked list in C Example of Iteration in C How to use atoi() function in C How to use floor() function in C How to use sine() function in C How to use Typedef Struct in C Integer Promotions in C C Program Swap Numbers in cyclic order Using Call by Reference C Program to Find Largest Number Using Dynamic Memory Allocation C Program to Find the Largest Number using Ternary Operator C/C++ Program to Find the Size of int, float, double and char Find the Largest Three Distinct Elements in an Array using C/C++ Loop Questions in C Modulus on Negative Numbers in C Multiplication table program in C using For loop Nested Loops in C Programming Examples C Program for Mean and Median of an Unsorted Array Results of Comparison Operations in C and C++ Reverse a Stack using Recursion in C Simple hash() function in C strcat() Function in C Sum of N numbers in C using For loop Use of free() function in C Write a program that produces different results in C and C++ C Function Argument and Return Values Keywords in C Bank management system in C Calendar application in C Floor() Function in C Free() Function in C How to delete a file in C How to move a text in C Remove an element from an array in C Unformatted input() and output() function in C What are linker and loader in C SJF Scheduling Program in C Socket Programming in C Structure in C Tower of Hanoi in C Union Program in C Variable Declaration in C What is Linked List in C While Loop Syntax in C fork() in C GCD program in C Branching Statements in C Comma Operator in C Control statement in C Double Specifier in C How to create a binary file in C Long int in C Palindrome Number in C Pure Virtual Function in C Run Time Polymorphism in C Types of Array in C Types of Function in C What is a buffer in C What is required in each C Program Associativity of Operators in C Bit Stuffing Program in C Actual and Formal Parameters Addition of two Numbers in C Advantages of function in C Arithmetic Progression Program in C Binomial Coefficient Program in C Difference between Array and List in C Diffie-Hellman Algorithm in C How to convert a number to words in C How to convert a string to hexadecimal in C Difference between If and Switch Statement in C C and C++ Binary Files C program that does not Suspend when Ctrl+Z is Pressed Different ways to Declare the Variable as Constant in C Range of Int in C C Program to find the size of a File FIFO Example in the C Language For loop in C Programming GCD program of two numbers in C GPA Calculator in C How to Calculate Time Complexity in C How to include graphics.h in C How to measure time taken by a function in C How to return a Pointer from a Function in C What is the main in C Addition of Matrix in C Booleans in C C Program for Extended Euclidean algorithms C Program of Fencing the Ground Ceil and Floor in C Compound Interest Program in C Displaying Array in C Distance Vector Routing Protocol Program in c Dos.h Header File in C Language DSA Program in C Explain the two-way selection in C Fee Management System in C File Operations in C Malloc function in C Multiplication Table in C Simple Programs in C Language tolower() Function in C Type Conversion in the C Why does sizeof(x++) not Increment x in C Advantages of Dynamic Memory Allocation in C Armstrong Number in C Assignment Operator Program in C Banker’s Algorithm in C Binary Search in C with Best and Worst Time Complexity Caesar Cipher Program in C Call by Value and Call by Reference in C Conditional Operator in C CRC Program in C Deadlock Detection Program in C Decimal to Binary in C Difference between If Else and Nested If Else in C Difference between Pre-increment and Post-increment in C Difference between Scope and Lifetime in C Evaluation of Arithmetic Expression in C Explain the Increment and Decrement Operators in C Fseek Function in C Functions in C How to Find Square Free Numbers in C Length of an Array Function in C OpenGL in C Projects on C language in 2023 Purpose of a Function Prototype in C Stdio.h in C Two-Dimensional array in C What is String Comparison in C C Compilers for Windows Functions and Recursion in C How to Declare Boolean in C How to Declare Character in C How to Round up a number in C How to use strlen() in C Pointer Declaration in C Algorithm for String Palindrome in C C Program to find ASCII value of a character Constant Pointer in C How to find string length in C using strlen() function Implicit and Explicit in C Indirect Recursion in C Input and Output functions in C isupper() in C Jump Statement in C Lifetime of a Variable in C Linker Error in C Language Numeric Constant in C Size of Pointer in C Square Root in C Language Static and Dynamic Memory allocation String Declaration in C Strong Number in C Symmetric Matrix in C Types of C Tokens What is a Size of Pointer in C What is Increment and Decrement Operator in C 1 2 3 4 Series Program in C Advantages and Disadvantages of C Language C Program for Polynomial Addition C Program to Count the Number of Vowels in a String C Programming Errors and Solutions Compilation Errors in C Complex C Programs Difference between Argument and Parameter in C Difference between char s[] and char *s in C Evaluation of Postfix Expression Using Stack in C Find Leftmost and Rightmost Set Bit of a Number fprintf and fscanf in C Introduction to Dynamic Array in C Print Address in C Realloc function in C Ternary Operators in C Types of Tokens in C with Examples Difference between Static and Dynamic Memory Allocation in C Addition Program in C Array Definition in C Array of Pointers in C Arrow Operator in C Average of Two Numbers in C Binary to Decimal in C Binary to Octal in C BREAK STATEMENT in C C Programming Operators Questions C Programs Asked in Interview Calculator Program in C C Program to Read and Print an Employee's Detail Using Structure Bubble Sort Algorithm in C C Program to Find Area and Perimeter of Circle C Program to Check Whether a Given Number is Even or Odd C in Roman Numerals C Program to Make a Simple Calculator Using Switch Case Insertion Sort Program in C How to take input in string in C GCC Conflicting Types in C Function Definition in C Format Specifier for Hexadecimal in C Flowchart in C Float in C Fizzbuzz Implementation in C Conditional Statement in C Conio.h functions list in C Constants in C Dynamic Array in C Decision Making Statements in C Continue Statement in C Creation of Thread in C DFS Algorithm in C Difference between parameter and arguments in C Dijkstra's Algorithm in C Leap Year Program in C Jump Statements in C Modulus Operator in C Memory Allocation in C Simple Interest Program in C Reverse Array in C Recursive Function in C Queue in C Printing Pascal’s Triangle in C Preprocessor Directives in C Perror() in C Perfect Number in C Programming Language Parameter Passing Techniques in C Pascal Triangle in C Patterm Program in C

String Declaration in C

What is string?

In C, a string is a sequence of characters (including letters, numbers, and symbols) stored in consecutive memory locations. The end of the string is indicated by a null character ('\0'), which is automatically added to the end of a string literal or a character array.

In C, a string is typically represented as an array of characters, where each character in the array represents a single element of the string. For example, the string "hello" would be represented in C as an array of characters: ['h', 'e', 'l', 'l', 'o', '\0'].

C does not have a built-in string data type like some other programming languages. Instead, strings are typically manipulated using a set of standard library functions like strlen, strcpy, strcat, and strcmp, which operate on arrays of characters. These functions are defined in the <string.h> header file.

String declaration in C

In C, a string is typically represented as an array of characters terminated by a null character ('\0').

To declare a string variable in C, you can use the following syntax:


char myString[SIZE];

Here, myString is the name of the string variable, and SIZE is the maximum number of characters in the string. This creates an array of characters called myString with SIZE elements.

You can also initialize the string with a string literal as follows:

char myString[] = "Hello, world!";

In this case, the size of the array is determined automatically based on the length of the string literal (including the null terminator).

For example:

Example 1:

// program to show how we declare string in C
#include <stdio.h>
#include <string.h>
int main() {
char greeting[20] = "Hello, ";
char name[10] = "John";
strcat(greeting, name);
printf("%s\n", greeting);
printf("The length of the string is %d\n", strlen(greeting));
if (strcmp(greeting, "Hello, John") == 0) {
printf("The strings are equal.\n");
    } else {
printf("The strings are not equal.\n");
return 0;


Hello, John
The length of the string is 11
The strings are equal.


In this program, we declare two character arrays called greeting and name. We initialize greeting with the string "Hello, " and name with the string "John". We then use the strcat function to concatenate name onto the end of greeting. We print the resulting string using printf.

We also use the strlen function to determine the length of the resulting string, and print that value to the console.

Finally, we use the strcmp function to compare the resulting string with the string "Hello, John". If the strings are equal, we print a message saying so. If they are not equal, we print a different message.

Example 2:

// program that demonstrates how to declare a string in a function in C
#include <stdio.h>
voidprintString(char* str) {
printf("%s\n", str);
int main() {
charmyString[] = "Hello, world!";
return 0;


Hello, world!


In this program, we declare a function called printString that takes a char* argument named str. This argument represents a pointer to a character array (i.e., a string).

Within the function, we use the printf function to print the string to the console.

In the main function, we declare a character array called myString and initialize it with the string "Hello, world!". We then call the printString function, passing myString as the argument.

When we run this program, we should see the string "Hello, world!" printed to the console.

This demonstrates how to pass a string as an argument to a function in C. Note that when you pass a string to a function, you are actually passing a pointer to the first character of the string. This means that any changes you make to the string within the function will affect the original string outside of the function as well.

Advantages of string in C

Using strings in C has several advantages:

  • Ease of use: Strings make it easy to work with text and manipulate it in various ways, such as concatenating strings, searching for substrings, and so on.
  • Standard library functions: C provides a rich set of standard library functions for working with strings, such as strlen, strcpy, strcat, strcmp, and many others. These functions make it easy to perform common operations on strings without having to write your own code.
  • Efficient memory usage: In C, a string is typically implemented as a character array, which is a contiguous block of memory. This makes it efficient to manipulate strings, since you can easily access any character in the string using array indexing.
  • Compatibility with other systems: C strings are a common way to represent text in many different programming languages and systems, making it easy to interface with other software and data formats.
  • Portability: C strings are supported by virtually all C compilers and can be used on a wide variety of platforms, including embedded systems and microcontrollers.

Overall, using strings in C can make it easier to work with text and simplify many common programming tasks.