how to count numbers under 5.5

[pinotje]

Hi all,

double numbers[] = {9.8, 5.3, 6.2, 5.5, 5.4, 7.7, 8.1, 3.7, 1.8, 4.6};

how can I count numbers thats 5.5 or lower?
in the example above it must be 5 numbers under 5.5


Thanks

[Fubarable]

Hi all,

double numbers[] = {9.8, 5.3, 6.2, 5.5, 5.4, 7.7, 8.1, 3.7, 1.8, 4.6};

how can I count numbers thats 5.5 or lower?
in the example above it must be 5 numbers under 5.5


Thanks

What do you think the steps should be? Can we see your attempt?

[pinotje]

What do you think the steps should be? Can we see your attempt?

I really don't know...

I have tried this:

if(numbers[i] < 5.5) { count++ }
System.out.println ("counted: " +count);

Which is certainly wrong...

[Fubarable]

You need two constructs for this to work. First you have to go through all of the numbers in the array -- what code structure will allow you to loop through each item in the array?

[pinotje]

You need two constructs for this to work. First you have to go through all of the numbers in the array -- what code structure will allow you to loop through each item in the array?

Do you mean this?:

for(int i=0; i<numbers.length; i++)

[Fubarable]

Do you mean this?:

for(int i=0; i<numbers.length; i++)

Yes, exactly, a for loop. You've posted the "control" portion of the loop, and the loop will also have a body that will be between curly braces, {}. In the loop body you'll use the if block, and then after the loop you'll print out the results.

Give it a try! :)

[Junky]

Beware when using floating point numbers in equality statements.

class DoubleTrouble {
    public static void main(String[] args) {
        int count = 0;
        double[] values = {1, 7.0, 5.4, 5.5, 5.6, 5.499999999999999999999999999999};
        for(double d : values) {
            if(d < 5.5) {
                count++;
            }
        }
        System.out.println(count);
    }
}

You would expect the output of the above code to be 3 but is in fact only 2.

[pinotje]

Yes, exactly, a for loop. You've posted the "control" portion of the loop, and the loop will also have a body that will be between curly braces, {}. In the loop body you'll use the if block, and then after the loop you'll print out the results.

Give it a try! :)

Thanks for your tip...

[pinotje]

Beware when using floating point numbers in equality statements.

class DoubleTrouble {
    public static void main(String[] args) {
        int count = 0;
        double[] values = {1, 7.0, 5.4, 5.5, 5.6, 5.499999999999999999999999999999};
        for(double d : values) {
            if(d < 5.5) {
                count++;
            }
        }
        System.out.println(count);
    }
}

You would expect the output of the above code to be 3 but is in fact only 2.

Wow Thanks!

This is exactly what I'm looking for!

[pinotje]

Can anyone tell me the difference between:

double[] numbers = new double[]{1.0, 1.5, 2.0, 2.5, 3.0, 3.5};

,

double[] numbers = {1.0, 1.5, 2.0, 2.5, 3.0, 3.5};

and

double numbers[] = {1.0, 1.5, 2.0, 2.5, 3.0, 3.5};

I've tried all those 3 codes, and they work the same for me...
Are these codes just the same?

[dpspine420]

yes all 3 are ways to do the same thing, although the first one is redundant. I personally prefer

double[] numbers = {values};