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C Programming: Convert a string to lowercase

C String: Exercise-22 with Solution

Write a program in C to convert a string to lowercase.

C Programming: Convert a string to lowercase

Sample Solution:

C Code:

#include<stdio.h>
#include<ctype.h>

int main()
{
	int ctr=0;
	char str_char;
	char str[100]; 
    
	printf("\n Convert a string to lowercase :\n");  
    printf("----------------------------------");      
    printf("\n Input a string in UPPERCASE : ");
    fgets(str, sizeof str, stdin);  
    printf(" Here is the above string in lowercase :\n ");    
	while (str[ctr])
	{
		str_char=str[ctr];
		putchar (tolower(str_char));
		ctr++;
	}
	return 0;
}

Sample Output:

 Convert a string to lowercase :
----------------------------------
 Input a string in UPPERCASE : THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG.
 Here is the above string in lowercase :
 the quick brown fox jumps over the lazy dog.

Flowchart :

Flowchart: Convert a string to lowercase

C Programming Code Editor:

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Previous: Write a program in C to convert a string to uppercase.
Next: Write a program in C to check whether a character is Hexadecimal Digit or not.

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C Programming: Tips of the Day

Is there a way to specify how many characters of a string to print out using printf()?

The basic way is:

printf ("Here are the first 8 chars: %.8s\n", "A string that is more than 8 chars"); 

The other, often more useful, way is:

printf ("Here are the first %d chars: %.*s\n", 8, 8, "A string that is more than 8 chars"); 

Here, you specify the length as an int argument to printf(), which treats the '*' in the format as a request to get the length from an argument.

You can also use the notation:

printf ("Here are the first 8 chars: %*.*s\n",
        8, 8, "A string that is more than 8 chars"); 

This is also analogous to the "%8.8s" notation, but again allows you to specify the minimum and maximum lengths at runtime - more realistically in a scenario like:

printf("Data: %*.*s Other info: %d\n", minlen, maxlen, string, info); 

The POSIX specification for printf() defines these mechanisms.

Ref: https://bit.ly/395Zj2j