String functions in C language with examples | strcpy, strcat, strcmp, strrev, strlen in C
We need to include string.h header file in a program to use string functions. Different string functions in c language are:
1. strcpy() function in C Language
strcpy() is one of the most popular String functions in c language . This function is used store a value in a string variable
Syntax :
strcpy(Str2,Str1);
Str2 is the string variable to store the value.
Str1 is the string value to be stored in string variable Str2.
We can’t use assignment operator = to assign a value to string variable. So we need to use strcpy() function to do that.
char name[20];
strcpy(name,”Amit”);
Program to demonstrate the use of strcpy() function in C. |
#include<stdio.h> #include<string.h> int main() { char name[20]; strcpy(name,”Rahul”); printf("name=%s",name); return(0); } |
Output |
name=Rahul
|
2. strcat() function in C Language
strcat() function is used to combine values of two string variables .
Syntax
strcat(Str2,Str1);
Str2 is the string variable whose value will be combined with another string value.
Str1 is the string value to be combined with string variable Str2.
Program to demonstrate the use of strcat() function in C. |
#include<stdio.h> #include<string.h> int main() { char name[30]=”Rahul”; strcat(name,” Singh”); printf("name=%s",name); return(0); } |
Output |
name=RahulSingh
|
Description of above program
In above program, string variable studentname contains value “Amit”. After applying strcat() function, its value will be concatenated with “ Singh” and the final value of string variable studentname would become Amit Singh.
3. strlen() function in C Language
strlen() function is used to count and return number of characters in a string value.
Syntax :
strlen(Str);
Str is the string value whose length we want to find.
Program to demonstrate the use of strlen() function in C. |
#include<stdio.h> #include<string.h> int main() { char name[30]="Rahul"; int num; num=strlen(name); printf("\nNumber of characters=%d",num); return(0); } |
Output |
Number of characters=5
|
Description of above program
In above program, string variable studentname contains value “Amit”. strlen() function finds number of characters in the value “Amit” in string variable studentname that contains 4 characters. So strlen() would return 4.
4. strrev() function in C Language
strrev() function is used to reverse the characters stored in a string value.
Syntax
strrev(Str);
Str is the string variable whose value we want to reverse.
Program to demonstrate the use of strrev() function in C. |
#include<stdio.h> #include<string.h> int main() { char name[20]=”Rahul”; strrev(name); printf("name=%s",name); return(0); } |
Output |
name=luhaR |
Description of above program
In above program, string variable name contains “Rahul”. strrev() reverses the value of name to make it luhaR.
5. strcmp() function in C Language
strcmp() function is used to compare two string values. 0 is returned if the values of strings being compared are same.
Syntax:
strcmp(Str1,Str2);
Here, Str1 and Str2 are string variables or constants which we want to compare.
Program to demonstrate the use of strcmp() function in C. |
#include<stdio.h> #include<string.h> int main() { char name[35]; strcpy(name,”Sumit”); if(strcmp(studentname,”Amit”)==0) cout<<”\nWelcome Amit”; else cout<<”Wrong User”; return(0); } |
Output |
Wrong User |
Description of above program
In this program, string variable name contains “Sumit”. String variable name has been compared with the string value Amit. Value of name i.e. sumit doesn’t match Amit so the output would be wrong user.
6. strcmpi() function in C Language
strcmpi() function is used to compare string values but capital letters and small letters are considered same. 0 is returned if the values of strings being compared are same.
Syntax:
strcmpi(Str1,Str2);
Here, Str1 and Str2 are string variables or constants which we want to compare.
Program to demonstrate the use of strcmpi() function in C |
#include<stdio.h> #include<string.h> int main() { char n1[30],n2[30]; printf("Enter a string value="); gets(n1); printf("Enter another string value="); gets(2); if(strcmpi(n1,n2)==0) printf("Same"); else printf("Not same"); return(0); } |
Output |
Enter a string value=Aman Enter another string value=AMAN Same |
Description of above program
In this program, string variable n1 contains value “Aman” and n2 contains “AMAN”. n1 and n2 contain same values with different cases. They are considered same so message “Same” gets displayed .
7. strlwr() function in C Language
strlwr() function converts the uppercase letters to lowercase letters in a string value.
Syntax:
strlwr(Str);
Str is the string variable whose value we want to convert into lower case.
Program to demonstrate the use of strlwr() function in C |
#include<stdio.h> #include<string.h> int main() { char sname[30]=”SUMIT”; strlwr(sname); printf("\nsname=%s",sname); return(0); } |
Output |
sname=sumit
|
Description of above program
In this program, string variable sname contains “Sumit”. strlwr() function converts the value into small case i.e. sumit.
8. strupr() function in C Language
strupr() function converts the small case letters to capital letters in a string value.
strupr(Str);
Str is the string variable whose value we want to convert into capital letters.
Program to demonstrate the use of strupr() function in C |
#include<stdio.h> #include<string.h> int main() { char sname[30]=”sumit”; strupr(sname); printf(“\nsname=%s”,sname); return(0); } |
Output |
sname=SUMIT |
Description of above program
In this program, string variable sname contains “sumit”. strupr() function converts the value into capital case i.e. “SUMIT”.