在Java中使用do while循环在中间以*和“ o”为中心打印菱形

Question

Im trying to print a Diamond with * and "o" in the centre using do while loop. I have already done this with For loop but unsure how to change it to while loop. Can anyone give some support.

public static void diamond1() {
        System.out.println("Diamond Height: " + DIAMOND_SIZE);
        System.out.println("Output for: For Loop");

        int noOfRows = DIAMOND_SIZE;

        //Getting midRow of the diamond
        int midRow = (noOfRows)/2;

        //Initializing row with 1
        int row = 1;

        //Printing upper half of the diamond
        for (int i = midRow; i > 0; i--)
        {
            //Printing i spaces at the beginning of each row
            for (int j = 1; j <= i; j++) {
                System.out.print(" ");
            }

            //Printing j *'s at the end of each row
            for (int j = 1; j <= row; j++) {
                System.out.print("* ");
            }

            System.out.println();

            //Incrementing the row
            row++;
        }

        //Printing lower half of the diamond
        for (int i = 0; i <= midRow; i++) {
            //Printing i spaces at the beginning of each row
            for (int j = 1; j <= i; j++) {
                System.out.print(" ");
            }

            //Printing j *'s at the end of each row
            int mid = (row+1) / 2;
            for (int j = row; j > 0; j--) {
            if(i==0 && j==mid) {
                System.out.print("o ");
            }
            else {
                System.out.print("* ");
            }
            }

            System.out.println();

            //Decrementing the row
            row--;
        }
    }

How would I go about doing this?

Answer 1

In general, a for loop like this:

for (command1; statement; command2){
    // Code to loop
}

is equal to this while loop:

command1;
while(statement){
    // Code to loop
    command2;
}

and equal to this do-while loop:

command1;
do{
    if (statement){
        // Code to loop
        command2;
    }
} while(true);

If it is certain that the first loop must happen then you can use the below do-while:

command1;
do{
    // Code to loop
    command2;
} while(statement);

Answer 2

Here you go :

public static void Diamond() {
    int DIAMOND_SIZE = 5;
    System.out.println("Diamond Height: " + DIAMOND_SIZE);
    System.out.println("Output for: For Loop");

    int noOfRows = DIAMOND_SIZE;

    //Getting midRow of the diamond
    int midRow = (noOfRows)/2;

    //Initializing row with 1
    int row = 1;

    int i = midRow;
    while(i > 0){
        //Printing i spaces at the beginning of each row
        int j = 1;
        while(j <= i){
            System.out.print(" ");
            j++;
        }

        //Printing j *'s at the end of each row
        j = 1;
        while(j <= row){
            System.out.print("* ");
            j++;
        }
        System.out.println();

        //Incrementing the row
        row++;

        i--;
    }

    i = 0;
    while(i <= midRow){
    //Printing i spaces at the beginning of each row
        int j = 1;
        while(j <= i){
            System.out.print(" ");
            j++;
        }

        //Printing j *'s at the end of each row
        int mid = (row+1) / 2;
        j = row;
        while(j > 0){
            if(i == 0 && j == mid)
                System.out.print("o ");
            else
                 System.out.print("* ");
            j--;
        }

        System.out.println();

        //Decrementing the row
        row--;
        i++;
    }
}