C Language Example - Loop Output of 26 Letters
Loop through and output the 26 letters.
In the following example, we use the variable `letter` to store the letter to be output, then use a `for` loop to repeat 26 times, outputting the letter and adding a space after each one.
Inside the loop, the `printf` function is used to output the value of the variable `letter`; `%c` is `printf`'s format specifier, used to output a character.
Example 1
#include <stdio.h>
int main() {
char letter = 'A'; // The value of 'A' in ASCII is 65
// Use a loop to print 26 letters
for (int i = 0; i < 26; i++) {
printf("%c ", letter);
letter++; // Increment the letter variable to get the ASCII code of the next letter
}
printf("\n");
return 0;
}
Another example:
Example 2
#include <stdio.h>
int main()
{
char c;
for(c = 'A'; c <= 'Z'; ++c)
printf("%c ", c);
return 0;
}
Run result:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
If you want to output lowercase letters, simply set the initial value of the variable `letter` to `'a'` (in ASCII code, the value of `'a'` is 97), and then use `letter++` inside the loop:
Example
#include <stdio.h>
int main() {
char letter = 'a'; // The value of 'a' in ASCII is 97
// Use a loop to print 26 lowercase letters
for (int i = 0; i < 26; i++) {
printf("%c ", letter);
letter++; // Increment the letter variable to get the ASCII code of the next letter
}
printf("\n");
return 0;
}
Run result:
a b c d e f g h i j k l m n o p q r s t u v w x y z
The following example lets you choose whether to input uppercase or lowercase:
Example - Output uppercase or lowercase letters
#include <stdio.h>
int main()
{
char c;
printf("Enter u to display uppercase letters, enter l to display lowercase letters:");
scanf("%c", &c);
if(c== 'U' || c== 'u')
{
for(c = 'A'; c <= 'Z'; ++c)
printf("%c ", c);
}
else if (c == 'L' || c == 'l')
{
for(c = 'a'; c <= 'z'; ++c)
printf("%c ", c);
}
else
printf("Error! Invalid character entered.");
return 0;
}
Run result:
输入 u 显示大写字母，输入 l 显示小写字母: l a b c d e f g h i j k l m n o p q r s t u v w x y zother extensions