double or float datatype doesn't addup properly in a loop?

Question

In a loop I am adding 0.10 till I reach the desired #, and getting the index. This is my code :

    private static int getIndexOfUnits(float units) {
    int         


        

Answer 1

I think this may be what you're looking for:

Java provides a class from the import package: import java.text.DecimalFormat called DecimalFormat. Its signature is:

DecimalFormat myFormat = new DecimalFormat("0.0");

It takes a String argument where you specify how you want the formatting to be displayed.

Here's how you can apply it to your code:

DecimalFormat myFormat;
private static int getIndexOfUnits(float units) {
myFormat = new DecimalFormat("0.0");
int index = -1;
float addup = 0.10f;
for(float i = 1.00f; i < units; i=(float)i+addup) {
    index++;
    System.out.println("I = " + myFormat.format(i) + " Index = " + index);
}

return index;

}

In your println, you can see that the DecimalFormat's class format() method is called on float i using the myFormat object reference to DecimalFormat - this is where the formatting takes place.