Printing out a Random Array

[Energizer100]

import java.util;

public class Compact
{
public static int[] randomArray (int n)
{
int[] a = new int[n];
for (int i = 0; i < a.length; i++)
{
a[i] = Math.random();
}
return a;
}

public static double[] printArray (double[] a)
{
for (int i = 0; i<a.length; i++)
{
return a[i];
}
}

public static void main(String args[])
{
System.out.prin tln("Test for printing " + printArray(a));
}
}


In the above code, what I am trying to do is create an array with random integers. The size of the array is 20. I don't know how to call the array...

[JosAH]

Have you tried to compile it and read what the compiler had to say about it? btw,
you can't call an array, you might yell 'yoohoo' at it but I'm sure it won't react nor
respond. Arrays are kind of stupid.

kind regards,

Jos

[Energizer100]

Have you tried to compile it and read what the compiler had to say about it? btw,
you can't call an array, you might yell 'yoohoo' at it but I'm sure it won't react nor
respond. Arrays are kind of stupid.

kind regards,

Jos

import java.util;

public class Compact
{
public static void main(String[] args)
{
public static int[] randomArray (int n)
{
int[] a = new int[n];
for (int i = 0; i < a.length; i++)
{
a[i] = Math.random();
}
System.out.prin tln (a);
}
}
}


this doesn't work for some reason, it says illegal start of expression at the randomArray method. and a semicolon is expected at the second to last bracket

[BigDaddyLH]

When your syntax is way off the mark, the resulting compiler messages may not be helpful, because the compiler is so confused. That is the case, here.

You nested the defintion of method randomArray inside method main. In other words, you wrote:

void f() {
    void g() {
        
    }
}

instead of

void f() {
    
}

void g() {
        
}

[Energizer100]

When your syntax is way off the mark, the resulting compiler messages may not be helpful, because the compiler is so confused. That is the case, here.

You nested the defintion of method randomArray inside method main. In other words, you wrote:

void f() {
    void g() {
        
    }
}

instead of

void f() {
    
}

void g() {
        
}

okay, one problem was fixed. But it still says "illegal start of expression" for the random array method.

[BigDaddyLH]

okay, one problem was fixed. But it still says "illegal start of expression" for the random array method.

I can only guess what your code looks like now. I suggest that when you are asking a question about a syntax error, you should post the relevant code.

[Energizer100]

I can only guess what your code looks like now. I suggest that when you are asking a question about a syntax error, you should post the relevant code.

srry

import java.util;

public class Compact
{
public static void main(String[] args)
{
public static int[] randomArray(int n)
{
int[] a = new int[n];
for (int i = 0; i < a.length; i++)
{
a[i] = Math.random();
}
}
System.out.prin tln (a);
}
}

[JosAH]

Your first line is wrong: you can't import a package, you import classes instead;
as in:

[code=java]
import java.util.*;
[/code]

Compilers can be real nitpickers (which is AGT (A Good Thing (tm)))

kind regards,

Jos

[BigDaddyLH]

You are still nesting method randomArray inside method main. See reply #4.

ps. If you use code tags, your code will be more readable in this forum.

[Energizer100]

[code=java]
import java.util.Array s;

public class Compact
{
public static void main(String[] args)
{
public static int[] randomArray(int n)
{
int[] a = new int[n];
for (int i = 0; i < a.length; i++)
{
a[i] = Math.random();
}
}
System.out.prin tln (a);
}
}
[/code]

Still doesn,t work, same error

[BigDaddyLH]

See reply #9 -- I think it was posted just as you were replying!

[Energizer100]

See reply #9 -- I think it was posted just as you were replying!

import java.util.Arrays;

public class Compact 
{
	public static int[] randomArray(int n)
	{
		int[] a = new int[n];
		for (int i = 0; i < a.length; i++)
		{
		a[i] = Math.random();
		}
		return a;
	}
		
		
	public static void main(String args[])
	{
		int k;
		
		System.out.println("The random array is: " + randomArray(k));
	}
}

It says i have a possible loss of precision at a[i] = Math.random()

[Laharl]

Math.random() returns a decimal value in the range 0 <= x < 1. Thus, it is not an integer, but rather a double or float (I'm guessing double). To resolve this, you need to either use the Random class (google it) or cast Math.random() to an integer after multiplying to get the range you want.

For 0<=x<10 (aka random numbers less than 10):
[CODE=java]
import java.util.Rando m; //util.* covers this
public class A {
public static void main(String[] args){
int[] a = new int[8];
for (int b = 0; b < a.length; b++)
a[b] = (int)(Math.rand om()*10);
}
}
[/CODE]

[Energizer100]

Math.random() returns a decimal value in the range 0 <= x < 1. Thus, it is not an integer, but rather a double or float (I'm guessing double). To resolve this, you need to either use the Random class (google it) or cast Math.random() to an integer after multiplying to get the range you want.

For 0<=x<10 (aka random numbers less than 10):
[CODE=java]
import java.util.Rando m; //util.* covers this
public class A {
public static void main(String[] args){
int[] a = new int[8];
for (int b = 0; b < a.length; b++)
a[b] = (int)(Math.rand om()*10);
}
}
[/CODE]

import java.util.Arrays;

public class Compact 
{
	public static void main(String args[])
	{	
		int a[] = new int[20];	
		
		public static int[] randomArray(int a)
		{			
			for (int i = 0; i < a.size() ; i++)
			{
				a[i] = (int)(Math.random() * 10);
			}
			System.out.println("The random array is: " + a);
		}
	}
}

Still didn't work.

[Energizer100]

import java.util.Arrays;

public class Compact 
{
	public static void main(String args[])
	{	
		int a[] = new int[20];	

		for (int i = 0; i < a.length ; i++)
			{
				a[i] = (int)(Math.random() * 10);
			}
	
		System.out.println("The random array is: " + a);
	
	}
}

Okay, it has random stuff in it when it is printed out and it doesn't go to 20.