Create a marker for range with switch statement in java

so I have an assignment that I need to use a switch statement to identify a marker for range of random values
The question is like this:

Using switch statements, please identify the different ranges. Hence, follow the suggested markers:

"o" for numbers between (0,5];

"x" for numbers between (5, 10];

"s" for numbers between (10, 15];

"*" for numbers bigger than 15;

import java.util.*;

public class Problem01 {
    public static void main(String[] args) {
        //create random integer
        Random ran = new Random();
        int sum = 0;
        for (int i = 1; i <= 10; i++ ) {
            int random = ran.nextInt(20);
            //Printing the random number
            System.out.print("Number " + "(" + random + "): ");

            //Loop to print markers
            for(int j = 1; j <= random; j++) {
               //I don't know how to use the switch statement at this point, I tried everything and nothing work
            }
        }
    }
}

I have searched on the internet a lot but none of the way work, can you guys help me, thanks a lot

You can do the following:

import java.util.*;

public class Problem01 {
    public static void main(String[] args) {
        //create random integer
        Random ran = new Random();
        int sum = 0;
        for (int i = 1; i <= 10; i++ ) {
            int random = ran.nextInt(20);
            //Printing the random number
            System.out.print("Number " + "(" + random + "): ");

            switch ((random-1)/5) {
                case 0:
                    System.out.println("o");
                    break;
                case 1:
                    System.out.println("x");
                    break;
                case 2:
                    System.out.println("s");
                    break;
                default: //to handle case where the number is bigger than 15
                    System.out.println("*");
                    break;

            }
        }
    }
}

I'm not sure why you needed the inner loop.

This is the generated output for the above program.

Number (1): o
Number (10): x
Number (5): o
Number (13): s
Number (9): x
Number (13): s
Number (6): x
Number (16): *
Number (16): *
Number (10): x

edit: There is no direct way to use custom ranges with switch statements. This has been answered here

The most straightforward solution would be just to use multiple case options for each number:

String s = "$";
switch (j) {
    case 1: case 2: case 3: case 4: case 5:
        s = "x"; break;
    case 6: case 7: case 8: case 9: case 10:
        s = "o"; break;
    case 11: case 12: case 13: case 14: case 15:
        s = "s"; break;
    default:
        s = "*"; break;
}
System.out.println(x);

A better advanced version is to divide the input parameter by 5 (correct by 1) to reduce the number of cases:

switch ((j - 1) / 5) {
    case 0:
        s = "x"; break;
    case 1:
        s = "o"; break;
    case 2:
        s = "s"; break;
    default:
        s = "*"; break;
}

Also it's possible to get rid of switch completely by calculating an index in the array using % operator:

public static final String[] OPTS = {"X", "O", "S", "*"};
//...
String s = j < 20 ? OPTS[(j - 1) / 5 % OPTS.length] : OPTS[OPTS.length - 1];

Update

Another workaround could be to use a class/enum wrapper for the range (though it would be using if inside):

public enum RANGE {
    X(0, 5, "x"),
    O(5, 10, "o"),
    S(10, 15, "s"),
    OTHER(0, -1, "*");

    private final int min;
    private final int max;
    private final String sym;

    RANGE(int min, int max, String sym) {
        this.min = min;
        this.max = max;
        this.sym = sym;
    }
        
    public String getSym() {return sym; }

    static RANGE from(int n) {
        return Arrays.stream(RANGE.values())
                     .filter(r -> r.min < n && n <= r.max)
                     .findFirst().orElse(RANGE.OTHER);
    }
}

// actually, switch seems redundant:
switch(RANGE.from(j)) {
    case X: // do something
        break;
    // ...
    OTHER:
    default:
        // no range found
        break;
}