Having issues with an array method

If you are incrementing i with 0.5, how do you expect array index to work in loop? Can you please double check the code.

Something like this will work. Idea is that array indexes increment in steps of 1 and not 0.5 as your loop is expecting.

public static double[] createDoubles(){
    double[] dArray= {10.0,10.5,11.0,11.5,12.0,12.5,13.0};
    double[] squareArray= new double[dArray.length];
    for(int i= 0; i< dArray.length; i++){
        squareArray[i]= dArray[i]* dArray[i];
    }
    for(double f: squareArray)
        System.out.println(f);
    return squareArray;
}

Try the following way:

public static double[] createDoubles(){
  double[] squareArray= new double[7];
  double number = 10.0;
  int i=0;
  while(number <= 13.0) {
     squareArray[i] = number*number;
     number = number + 0.5;
     i++; 
  }
}
return squareArray;

You can see the following demo:

int i = 0;
i = i + 0.5;

The i will always be 0. That means your method will not stop when you invoke it.

Here's one way to do it, but probably not what the teacher wants:

public static double[] createDoubles() {
   double[] answer = {10.0, 10.5, 11.0, 11.5, 12.0, 12.5, 13.0 );
    // Actually, the above values should be 100,m ... 169.
    // but I'm too laze to do the math
   return answer;
}

Note that it is never a good idea to increment a loop index by a non-integer value. You might be surprised if you tried your method for increments of 0.1 instead of 0.5.

The reason this code isn't running but isn't working is because java is rounding down the i+=0.5 to i+=0, which is causing i to remain equal to 0, your loop never to exit, and your code not to do anything at all. To fix this part of your code, change the i+=0.5 to i+=1. However, as you do not declare anything in the square array, the resulting array that you return is nothing but 0s. Fix that by defining whatever you want in the d array, and multiplying those values together to create the values in the array you want to return. Or, you could simply declare put each value into the array like so:

for(int i= 0; i<= dArray.length-1; i+=1){
   squareArray[i]= Math.pow(10 + (0.5*i), 2);
}

squareArray[integer+double] is not a valid array index. Array index are always integer.