Update Array Elements from User Input | How-To Guide for Homework Assignments

[charmedbeauty]

Homework Statement

I have a simple 8X8 array with initial conditions.

how would I go about updating the an element of this array from user input?

Homework Equations

The Attempt at a Solution

for(i=0;i<MAX_SIZE;i++){
 24        putchar(i+'1');
 25        putchar('|');
 26 
 27        for(j=0;j<MAX_SIZE;j++){
 28 
 29          if((i==0 && j==0) || (i==0 && j==7) || (i==7 && j==0) || (i==7 && j==7)){
 30             printf("X");
 31             array[i][j] = X;
 32           }
 33             else if((i==3 && j==3) || (i==4 &&j==4)){
 34                printf("w");
 35           }  else if((i==3 && j==4) || (i==4 && j==3)){
 36                 printf("b");
 37           }  else {
 38             array[i][j]= '.';
 39             printf(".");
 40          }

my initial array


however now I have a user input a number and letter

ie input user : "b3"

i have read input using



char letter = getchar()
int number = getchar()
now how would I get the element b3 ([1][2]) to swap from '.' to 'b'

and then reprint the updated array?

I tried this

             i=letter;
 80        j=number;
 81 
 82        array[i][j] = 'b';
 83 
 84        printf("b");

obviously this just prints 'b' though.

 

[KataKoniK]

To update the element at position [1][2], you would need to use the assignment operator (=) to assign the value 'b' to the element at that position in the array. So your code could look something like this:

// declare variables for user input
char letter;
int number;

// get user input
printf("Please enter a letter: ");
letter = getchar(); // assuming the user enters 'b'
printf("Please enter a number: ");
number = getchar(); // assuming the user enters '3'

// convert letter to array index
int i = letter - 'a'; // this will give you the index 1 (since 'a' is 97 in ASCII and 'b' is 98, so 98-97=1)

// convert number to array index
int j = number - 1; // this will give you the index 2 (since the user entered '3', which is 51 in ASCII and 51-48=3, so 3-1=2)

// update the element at position [1][2]
array[j] = 'b';

// reprint the updated array
for(i=0;i<MAX_SIZE;i++){
putchar(i+'1');
putchar('|');
for(j=0;j<MAX_SIZE;j++){
printf("%c", array[j]); // use %c to print the character at that position in the array
}
printf("\n");
}