How to return all float values ?from an array in java?

Question

I only return the last value, please, help me to return all values

public static float[] generatePatientsTemperatures(int patientsCount) {
        float[] patientsTemperature = new float[patientsCount];
        for (int i = 1; i < patientsCount; i++) {
            patientsTemperature[i] = Math.round(((float) (Math.random() * 8) + 32) * 100) / (float) 100.0;
        }
    
        return patientsTemperature;

Answer 1

tl;dr

If you asking why your resulting array has one less element than expected, it is because of your initialization of i variable in your for loop.

? Change int i = 1 to int i = 0.

An array does hold all values

You are returning all the values. That is what an array does: holds a series of values. Your code successfully returns an array full of float primitive values.

Example code

I suggest using ThreadLocalRandom rather than Math.random because it offers some simple and handy methods. And it makes you future-proof if you ever do multi-threading.

You need to change your i = 1 to i = 0 to get the right number of elements in your results. Perhaps this is what your Question meant to ask, “Why am I getting one less element in my array than expected?”. Your initialization of i would be the cause of that problem.

public static float[] generatePatientsTemperatures ( final int patientsCount )
{
    float[] patientsTemperature = new float[ patientsCount ];
    for ( int i = 0 ; i < patientsCount ; i++ )
    {
        patientsTemperature[ i ] = ThreadLocalRandom.current().nextInt(320,450) * 0.1F;
    }
    return patientsTemperature;
}

Try that code. To see all the values of the array as text, call the utility method Arrays.toString( yourArrayHere ).

float[] temps = App.generatePatientsTemperatures( 3 );
String output = Arrays.toString( temps );

When run:

output = [35.5, 37.100002, 34.3]

Access each element in the array by annoying zero-based counting: zero for the first element, 1 for the second element, and so on.

float first = temps[ 0 ] ;
float second = temps[ 1 ] ;
float third = temps[ 2 ] ;

---

List

Working with List is easier than array.

List holds object references only, no primitive values allowed. Java has an auto-boxing feature to automatically turn your float primitives into Float objects. Just redefine your array to hold Float rather than float.

Tip: List.of produces an unmodifiable collection.

public static List < Float > generatePatientsTemperatures ( final int patientsCount )
{
    Float[] patientsTemperature = new Float[ patientsCount ];
    for ( int i = 0 ; i < patientsCount ; i++ )
    {
        patientsTemperature[ i ] = ThreadLocalRandom.current().nextInt( 320 , 450 ) * 0.1F;  // Auto-boxed from `float` primitive to `Float` object.
    }
    List < Float > results = List.of( patientsTemperature );
    return results;
}

Some code to run it.

List < Float > temps = App.generatePatientsTemperatures( 3 );
String output = temps.toString();

output = [32.8, 43.600002, 35.5]