Thread: calling a fucntion in a switch operator

i just started C and i'm doing a program for a class i'm taking and it requires the usage of a menu (i'm using a switch operator for this) and multiple functions in order to manipulate an image (i.e. load, save, make negative, flip...etc.) i'm having problems calling a function in the switch operator. i keep getting the error: syntax error before fuction...


any help is greatly appreciated!


this is what i have so far:

Code:

void PrintMenu();
/* read image from a file */
int ReadImage(char fname[SLEN], unsigned char R[WIDTH][HEIGHT], unsigned char G[WIDTH][HEIGHT],
unsigned char B[WIDTH][HEIGHT]);
/* save a processed image */
void SaveImage(char fname[SLEN], unsigned char R[WIDTH][HEIGHT], unsigned char G[WIDTH][HEIGHT],
unsigned char B[WIDTH][HEIGHT]);

/*   begin function PrintMenu   */
void PrintMenu()
{
	int operator;
	
	/* begin while loop */
	while( operator != 11 )	/*  program continues until input of 9   */
	{
		printf( "\n1: Load a PPM image" );
		printf( "\n2: Save an image in JPEG format" );
		printf( "\n3: Make a negative of an image" );
		printf( "\n4: Flip an image horizontally" );
		printf( "\n5: Flip an image vertically" );
		printf( "\n6: Detect image edges" );
		printf( "\n7: Add noise to an image" );	
		printf( "\n8: Image quantization" );	
		printf( "\n9: Add borders to an image" );	
		printf( "\n10: Image Overlay" );
		printf( "\n11: Exit\n" );	
	
		printf( "\nEnter your choice:" );
		scanf( "%d", &operator );
		
		
		switch( operator )
			{
			case 1:
				i get an error here, it says "syntax error before char"-->ReadImage(char fname[SLEN], unsigned char R[WIDTH][HEIGHT], unsigned char G[WIDTH][HEIGHT],
unsigned char B[WIDTH][HEIGHT]);
				break;
			
			case 2:
				void SaveImage(char fname[SLEN], unsigned char R[WIDTH][HEIGHT], unsigned char G[WIDTH][HEIGHT],
unsigned char B[WIDTH][HEIGHT]);
				break;
......and so on.

please tell me what i'm doing wrong.

Well.. you used a function declaration instead of a function call... Which leads me to think that you don't understand half of your own code because you just pasted something you found on the net. Am I close ?

PLEASE USE CODE TAGS

Code:

ReadImage(char fname[SLEN], unsigned char R[WIDTH][HEIGHT], unsigned char G[WIDTH][HEIGHT],
unsigned char B[WIDTH][HEIGHT]);

This not the way you will call the function. I would really suggest you to look into some basic concepts of on how to call a function. Read this

You wont be sending the data types of your variable as an argument when calling a function. Instead you would just send the variables as your parameter to the function. Like this

Code:

ReadImage(fname, R, G,B);

ssharish

Originally Posted by pankaj401

Code:

int operator;
	
/* begin while loop */
while( operator != 11 )	/*  program continues until input of 9   */

You also need to initialize operator before using it.

And the comment and the code don't match. Perhaps simply removing the comment would do just as much good? It's not like this bit is extremely difficult to understand.

--
Mats