If statement in while statement doesn't work (java)

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I tried to make a couple lines that checks if a random generated number is equal to a number of other integers if it's not, it returns that number, if not it repeats.

Here's the code:

Java

static int sum1;
static int sum2 = 1;
static int sum3 = 2;
static int num1 = 3;
static int num2 = 4;
static int num3 = 5;
static int dum1 = 6;
static int dum2 = 7;
static int dum3 = 8;


public static int getNumbers()
{
    int holder;
    boolean numFound = false;
    holder = 1 + (int) (Math.random() * 9);
    while(numFound = false)
    {
        if (holder == 0)
        {
            holder = 1;
            if (holder!=sum1 && holder!=sum2 && holder!=sum3 && holder!=num1 && holder!=num2 && holder!=num3 && holder!=dum1 && holder!=dum2 && holder!=dum3)
            {
                numFound = true;
            }
        } else {
            if (holder!=sum1 && holder!=sum2 && holder!=sum3 && holder!=num1 && holder!=num2 && holder!=num3 && holder!=dum1 && holder!=dum2 && holder!=dum3)
            {
                numFound = true;
            }
        }
    }

It should just print out 9 eventually. But, it just prints out random numbers like the while statement isn't even there. What's wrong?

What I have tried:

I've tried changing the

Java

Math.random()

method into the java.util.Random,

Java

Random rand = new Random(9)

Posted 10-Jul-18 6:23am

Member 13906110

Updated 10-Jul-18 13:49pm

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OriginalGriff · Answer 1 · 2018-07-10T07:16:00

Solution 1

"=" is an assignment, not a comparison:

while(numFound = false)

Try:

while(numFound == false)

Posted 10-Jul-18 7:16am

OriginalGriff

Mohibur Rashid · Answer 2 · 2018-07-10T13:49:00

Original Griff already answered your question. Let me improve your overall coding.

// all these sum, num, dum, can't you think something better? How about array?
static int sum1; // You are using default value of sum1; clever but bad practice; 
static int sum2 = 1;
static int sum3 = 2;
static int num1 = 3;
static int num2 = 4;
static int num3 = 5;
static int dum1 = 6;
static int dum2 = 7;
static int dum3 = 8;


public static int getNumbers()
{
    int holder;
    boolean numFound = false;
    holder = 1 + (int) (Math.random() * 9);
    // even if you write the right syntax as OriginalGriff suggested. And your holder is not between 0-8; your function will stuck in an infinte loop. because holder is going to be always false
    while(numFound = false)
    {
        if (holder == 0)
        {
            holder = 1;
            if (holder!=sum1 && holder!=sum2 && holder!=sum3 && holder!=num1 && holder!=num2 && holder!=num3 && holder!=dum1 && holder!=dum2 && holder!=dum3)
            {
               // if your code reach here, you code will not reach else. common sense; but if you code do not reach here why do you think it will reach if of "else"?
                numFound = true;
            }
        } else {
            if (holder!=sum1 && holder!=sum2 && holder!=sum3 && holder!=num1 && holder!=num2 && holder!=num3 && holder!=dum1 && holder!=dum2 && holder!=dum3)
            {
                numFound = true;
            }
        }
    }

How to solve? fix few issues
1. How about instead of declaring each number, declare then as array
2. Move holder generation inside the while loop; so, if the if condition say false it will regenerate the number
3. to check whether number belongs to array, either write a function to check if the array contains your generated number or you can use the following suggestion, described in stackoverflow java - How can I test if an array contains a certain value? - Stack Overflow[^]