String | C Programming Strings (With Examples)

Hi, I'm Golam Rabbani. Today I will discuss about string
in c program.

Greetings! How are you all? Hope everyone is well.

At first we have to know that what is string?

Answer: Strings are defined as an array of characters.

String terminated by a null character '\0'.
you must use in string.h header file.

For e.g. “string”;

s

t

r

i

n

g

\0

How to declare a string?

Char s[4];

s[0]

s[1]

s[2]

s[3]

How many way to initialize strings?

Type 1: char s[15] = “Hello world”;

Type 2: char s[] = “Hello world”;

Type 3: char s[15] = {‘H’,’e’,‘l’,’l’,‘o’,’\0’};

Type 4: char s[] = {‘H’,’e’,‘l’,’l’,‘o’,’\0’};

Let’s go……..

Example 1: Read a string.

#include<stdio.h>
#include<string.h>
int main(){
    char name[55] = "My name is Golam Rabbani";
    printf("%s", name);
    return 0;
}
// Just Basic

Output: My name is Golam Rabbani

Example 2: scanf() to read a string.

#include<stdio.h>
#include<string.h>
int main(){
    char name[55];
    printf("Enter string: ");
    scanf("%s", &name);
    printf("Output: %s", name);
    return 0;
}
// Use scanf

Enter string: Hi user
Output: Hi user

Example 3: gets() & puts() to read a string.

#include<stdio.h>
#include<string.h>
int main(){
    char name[55];
    printf("Enter character: ");
    gets(name);//for input character.
    printf("Output: ");
    puts(name);//for output character.
    return 0;
}
// Use gets & puts

Enter character: Hello world!
Output: Hello world!

Type of String function:

1. strlen() - calculates length of a string
2. strcpy() - copies a string to another
3. strcmp() - compares two strings
4. strcat() - concatenates two strings
5. strchr() - searches the occurrence of a specified
character in the given string.

#strlen(): length of string.

e.g. H e l l o

    1 2 3 4 5

Length = 5

Question 1: Write a program to find the string length.

#include<stdio.h>
#include<string.h>
int main(){
    char name[55] = "Golam Rabbani";
    int count;
    count = strlen(name);
    printf("%d", count);
    return 0;
}
// String Length

Length: 13

Question 2: Write a program to find the string length
without using strlen() function.

#include<stdio.h>
#include<string.h>
int main(){
    char name[55];
    int i,count=0;
    printf("Enter string: ");
    gets(name);
    for(i=0; name[i]!='\0'; i++){
        count++;
    }
    printf("Length: %d",count);
    return 0;
}
// String length without
// build in function.

Enter string: hello
Length: 5

#strcpy(): Copies a string to another.

e.g. a=50; and b=20;

If strcpy(a,b); a←b

Result a=20

Program:

#include<stdio.h>
#include<string.h>
int main(){
    char fname[55] = "Golam";
    char lname[55] = "Rabbani";
    strcpy(fname, lname);
    printf("%s", fname);
    return 0;
}
//just copy and change

Output: Rabbani

#strcmp(): Compares two strings.

e.g. string a=bd; and string b=bd;

If a==b

Right Answer

Else

Wrong Answer

Program:

#include<stdio.h>
#include<string.h>
int main(){
    char a[10] = "Hi";
    char b[10] = "Hi";
    if(strcmp(a,b)==0){
        //if a==b, result 0
        //so 0==0 right.
        printf("Right Answer!");
    }
    else{
        printf("Wrong Answer!");
    }
    return 0;
}

Output: Right Answer!

#strcat(): Concatenates two strings.

e.g. a=”Hi”; b=”world”;

Concatenates means a+b;

If a+b; result is Hi world.

Program:

#include<stdio.h>
#include<string.h>
int main(){
    char fname[55] = "Hi,";
    char lname[55] = "Golam Rabbani";
    strcat(fname, lname);
    printf("%s\n%s", fname, lname);
    return 0;
}
// Concatenation string, Add string

Output: Hi, Golam Rabbani

#strchr(): Searches the occurrence of a specified
character in the given string.

e.g. a=”Md - Golamrabbani”;

b=”-”;

Result - Golamrabbani

Program:

#include<stdio.h>
#include<string.h>
int main(){
    char fname[55] = "Golam - Rabbani";
    char lname = '-';
    char *n;
    n=strchr(fname, lname);
    printf("%s", n);
    return 0;
}
// String Character

Output: - Rabbani

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