Query: Receiving array from functions

[wirefree101]

Greetings.

I seek assistance understanding the procedure for passing (receiving) arrays to (from) functions. The following code is indicative of my misunderstanding:

#include <stdio.h>

char retArr(char []);

int main(){
	char tempArr[5];
	char rcvArr[5];
	
	rcvArr = retArr(tempArr);
	
	printf("rcvArr[0]: %c\n", rcvArr[0]);
	return 1;
}

char retArr(char arr[]){
	arr[0] = 'A';
	arr[1] = 'B';
	arr[2] = 'C';
	arr[3] = 'D';
	arr[4] = 'E';

	return arr[];
}

Would greatly appreciate advise & assistance.

Best regards,
wirefree101

[tabstop]

You don't receive an array from a function. You pass an array to a function like you pass anything else to a function, but any changes you make to that array are seen in the original main.

[Sebastiani]

1) return arr[] is not a valid expression.
2) Your function returns a single char, FYI.
3) You can't return an array by value in C. You can return a pointer, but just keep in mind that it can't be to a local variable.
4) You can define a structure that contains an array and pass it around by value, but just keep in mind that it can't hold a pointer to an array of values, just a fixed-size buffer, eg:

#define ARRAY_HOLDER_BUFFER_LENGTH 5

struct array_holder
{
      char data[ ARRAY_HOLDER_BUFFER_LENGTH ];
};

[Adak]

Greetings.

I seek assistance understanding the procedure for passing (receiving) arrays to (from) functions. The following code is indicative of my misunderstanding:

#include <stdio.h>

char retArr(char []); //this is global, all functions can work with it, no passing needed.

int main(){
                        //char tempArr[5]; not needed
        int i;
	char rcvArr[5];
	
	/*tempArr (the name of the array, is actually pointing to the base of the array with 
          it's name. No return type is needed for an array that you send to a function.
       */
        retArr[rcvArr);  //is all you need tempArr is not needed at all
                     // rcvArr = retArr(tempArr);
	
	//let's make it a full-blown peep show, instead: :)
        for(i = 0; i < 5; i++)
           printf("rcvArr[%d]: %c\n", i, rcvArr[i]);
                  // printf("rcvArr[0]: %c\n", rcvArr[0]);
	return 1;
}


void retArr(char arr[]){  //arr is now another name for rcvArr[] - same array though
	arr[0] = 'A';
	arr[1] = 'B';
	arr[2] = 'C';
	arr[3] = 'D';
	arr[4] = 'E';

	//no return needed
}

Hope that helps.

[wirefree101]

All advise much appreciated.

Best regards,
wirefree101