C++ help

LivDawg · 05-06-2009, 10:09 AM

Hi just wondering if anyone has any code that changes a uppercase letter to lowercase and visa versa...

I've declared 2 arrays and an alpha above all my functions that are
char lower[] = **'a','b','c'...rest letters..'z'}
char Upper[] = **'A','B','C'...rest letters...'Z'}
Int alpha
The code I got so far for the functions (toLower & toUpper) is

char toLowerCase(char c)
for(int i=0; lower!='\0'; i++)
**
If(c==lower)
**
(Maybe more code here?)
return lower;
}
else
return false;
}//end for
}//end function
char toUpperCase(char c)
**
for(int i=0; lower!='\0'; i++)
**
If(c==upper)
**
(Maybe more code here?)
return true;
}
else
return false;
}//end for
}//end function

I don't know what other code to put in there to make it change to uppercase

FredT · 05-08-2009, 05:37 PM

Here's what I came up with (for some reason, the brackets turn to ** on the forum, so take that into account):

Code:

#include <stdio.h>

/* Alphabet arrays */
char upperChars[26] = **'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'};
char lowerChars[26] = **'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'};

/* Characters through the various stages */
char currentChar, newChar, changed;

/* Declare the function to be used below */
char convertChar(char);

int main()**
	while(TRUE)** /* Keep this going on and on until the user quits */
		printf("Enter a character: ");
		scanf("%c", &currentChar); /* Get the user's input */
		newChar = convertChar(currentChar); /* Runs the conversion function below */
		printf("Opposite case is is: %c\n", newChar); /* Printf the results */
	}
	return 0;
}

/* The conversion function */
char convertChar(char toBeChanged)**
	for(int i=0; i<26; i++)** /* Loop through all the letters of the alphabet */
		if(toBeChanged == upperChars[i])** /* If the user's char is equal to the letter we're on in the for loop... */
			changed = lowerChars[i];  /* set it equal to the char in the same position in the opposite array */
		}
		else if(toBeChanged == lowerChars[i])**
			changed = upperChars[i];
		}
	}
	return changed;
}

FredT · 05-08-2009, 05:41 PM

Sorry, I just tested that now and I got 2 errors...

1) Declare int i outside the for loop
2) while(TRUE) is incorrect, set a boolean variable equal to true and use that, if you want the program to keep looping.

Here it is with the changes in place:

Code:

#include <stdio.h>

/* Alphabet arrays */
char upperChars[26] = **'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'};
char lowerChars[26] = **'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'};

/* Characters through the various stages */
char currentChar, newChar, changed;

/* Declare the function to be used below */
char convertChar(char);

/* Declare the loop bool */
int loop = 1;

int main()**
	while(loop)** /* Keep this going on and on until the user quits */
		printf("Enter a character: ");
		scanf("%c", &currentChar); /* Get the user's input */
		newChar = convertChar(currentChar); /* Runs the conversion function below */
		printf("Opposite case is is: %c\n", newChar); /* Printf the results */
	}
	return 0;
}

/* The conversion function */
char convertChar(char toBeChanged)**
	int i;
	for(i=0; i<26; i++)** /* Loop through all the letters of the alphabet */
		if(toBeChanged == upperChars[i])** /* If the user's char is equal to the letter we're on in the for loop... */
			changed = lowerChars[i];  /* set it equal to the char in the same position in the opposite array */
		}
		else if(toBeChanged == lowerChars[i])**
			changed = upperChars[i];
		}
	}
	return changed;
}

05-06-2009, 10:09 AM	#1 (permalink)
LivDawg Registered User Join Date: Apr 2009 Location: Australia Posts: 2 OS: Windows Vista	C++ help Hi just wondering if anyone has any code that changes a uppercase letter to lowercase and visa versa... I've declared 2 arrays and an alpha above all my functions that are char lower[] = 'a','b','c'...rest letters..'z'} char Upper[] = 'A','B','C'...rest letters...'Z'} Int alpha The code I got so far for the functions (toLower & toUpper) is char toLowerCase(char c) for(int i=0; lower!='\0'; i++) If(c==lower) (Maybe more code here?) return lower; } else return false; }//end for }//end function char toUpperCase(char c) for(int i=0; lower!='\0'; i++) If(c==upper) ** (Maybe more code here?) return true; } else return false; }//end for }//end function I don't know what other code to put in there to make it change to uppercase