C programs to change the case of a string have been shown here. A string can be converted into various cases like uppercase, lowercase, sentence case, capitalized case, toggle case, alternating case etc.
Page Contents:
1. Program & Output: to uppercase using ASCII manipulation
2. Program & Output: to uppercase using strupr()
3. Program & Output: to lowercase using ASCII manipulation
4. Program & Output: to lowercase using strlwr()
5. Program & Output: to sentence case
6. Program & Output: to capitalized case
1. C Program & output to convert a string to uppercase using ASCII value manipulation
Code has been copied
/****************************************** alphabetacoder.com C Program to convert a string to uppercase using ASCII value manipulation *******************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i = 0; // take input of string printf("Enter a string: "); gets(str); // check each charcater in the string str. change // each lowercase letter to its uppecase equivalent. // Make no change for other characters. while (str[i] != '\0') { // check if character is in lowercase // If yes, subtract 32 from its ASCII if (str[i] >= 'a' && str[i] <= 'z') { str[i] = str[i] - 32; } i++; } printf("The string in uppercase: %s\n", str); return 0; }
Output
Enter a string: a qUick brown foX
The string in uppercase: A QUICK BROWN FOX
2. C Program & output to convert a string to uppercase using strupr()
Code has been copied
/**************************** alphabetacoder.com C Program to convert a string to uppercase using strupr() ******************************/ #include<stdio.h> #include<string.h> int main() { // delclare variables char str[100]; // take input of string printf("Enter a string: "); gets(str); // convert and display the string str // to uppercase using the function strupr() printf("The string in uppercase: %s\n", strupr(str)); return 0; }
Output
Enter a string: a qUick brown foX
The string in uppercase: A QUICK BROWN FOX
3. C Program & output to convert a string to lowercase using ASCII value manipulation
Code has been copied
/****************************************** alphabetacoder.com C Program to convert a string to lowercase using ASCII value manipulation *******************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i = 0; // take input of string printf("Enter a string: "); gets(str); // check each charcater in the string str. change // each lowercase letter to its uppecase equivalent. // Make no change for other characters. while (str[i] != '\0') { // check if character is in lowercase // If yes, subtract 32 from its ASCII if (str[i] >= 'A' && str[i] <= 'Z') { str[i] = str[i] + 32; } i++; } printf("The string in lowercase: %s\n", str); return 0; }
Output
Enter a string: A QUICK BROWN FOX
The string in lowercase: a quick brown fox
4. C Program & output to convert a string to lowercase using strlwr()
Code has been copied
/******************************** alphabetacoder.com C Program to convert a string to lowercase using strlwr() *********************************/ #include<stdio.h> #include<string.h> int main() { // delclare variables char str[100]; // take input of string printf("Enter a string: "); gets(str); // convert and display the string str // to lowercase using the function strlwr() printf("The string in lowercase: %s\n", strlwr(str)); return 0; }
Output
Enter a string: A QUICK BROWN FOX
The string in lowercase: a quick brown fox
5. C Program & output to convert a string to sentence case
Code has been copied
/********************************************* alphabetacoder.com C Program to convert a string to sentence case **********************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i; // take input of string printf("Enter a string: "); gets(str); // capitalize the first letter of first word. if (str[0] != '\0') { if (str[0] >= 'a' && str[0] <= 'z') { str[0] = str[0] - 32; } } // increment i to start checking from next character i++; // Keep the other letters in lower-case while (str[i] != '\0') { // check if characters is in uppercase // If yes, add 32 from its ASCII if (str[i] >= 'A' && str[i] <= 'Z') { str[i] = str[i] + 32; } i++; } printf("The string in the sentence case: %s\n", str); return 0; }
Output
Enter a string: how are you?
The string in the sentence case: How are you?
6. C Program & output to convert a string to capitalized case
Code has been copied
/************************************************* alphabetacoder.com C Program to convert a string to capitalized case ***************************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i; // take input of string printf("Enter a string: "); gets(str); // capitalize the first letter of first word. if (str[0] != '\0') { if (str[0] >= 'a' && str[0] <= 'z') { str[0] = str[0] - 32; } } // increment i to start checking from next character i++; // capitalize the first letter of each word while (str[i] != '\0') { // check if previous charcater is a space. // It indicates the starting of new word if (str[i - 1] == ' ') { // check whether the current charcater is in lowercase // If yes, then make it uppercase if (str[i] >= 'a' && str[i] <= 'z') { str[i] = str[i] - 32; } } // convert other uppercase letters to lowercase else if (str[i] >= 'A' && str[i] <= 'Z') { str[i] = str[i] + 32; } i++; } printf("The string in the capitalized case: %s\n", str); return 0; }
Output
Enter a string: it is c programming.
The string in the capitalized case: It Is C Programming.
7. C Program & output to convert a string to toggle case
Code has been copied
/******************************************* alphabetacoder.com C Program to convert a string to toggle case *********************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i; // take input of string printf("Enter a string: "); gets(str); // convert each uppercase letter to lowercase // and convert each lowercase letter to uppercase while (str[i] != '\0') { // check if character is in uppercase // If yes, add 32 from its ASCII if (str[i] >= 'A' && str[i] <= 'Z') { str[i] = str[i] + 32; } // check if character is in lowercase // If yes, subtract 32 from its ASCII else if (str[i] >= 'a' && str[i] <= 'z') { str[i] = str[i] - 32; } i++; } printf("The string in the toggle case: %s\n", str); return 0; }
Output
Enter a string: Hello World
The string in the toggle case: hELLO wORLD
8. C Program & output to convert a string to alternating case
Code has been copied
/************************************************* alphabetacoder.com C Program to convert a string to alternating case ***************************************************/ #include<stdio.h> int main() { // delclare variables char str[100]; int i; // take input of string printf("Enter a string: "); gets(str); // convert each word to alternating case // start with lowercase then uppercase, and so on while (str[i] != '\0') { // odd position charcater should be in lowercase if (i % 2 == 0) { if (str[i] >= 'A' && str[i] <= 'Z') { str[i] = str[i] + 32; } } // even position character should be in uppercase else { if (str[i] >= 'a' && str[i] <= 'z') { str[i] = str[i] - 32; } } i++; } printf("The string in the alternating case: %s\n", str); return 0; }
Output
Enter a string: a quick brown fox jumps over a lazy dog
The string in the alternating case: a qUiCk bRoWn fOx jUmPs oVeR A LaZy dOg