A Java “approximately equal” method (function)

As a quick note, here’s the source code for a Java “approximately equal” function that I use in an Android application:

/**
 * determine whether two numbers are "approximately equal" by seeing if they
 * are within a certain "tolerance percentage," with `tolerancePercentage` given
 * as a percentage (such as 10.0 meaning "10%").
 *
 * @param tolerancePercentage 1 = 1%, 2.5 = 2.5%, etc.
 */
public static boolean approximatelyEqual(float desiredValue, float actualValue, float tolerancePercentage) {
    float diff = Math.abs(desiredValue - actualValue);         //  1000 - 950  = 50
    float tolerance = tolerancePercentage/100 * desiredValue;  //  20/100*1000 = 200
    return diff < tolerance;                                   //  50<200      = true
}

You call the function like this:

boolean closeEnough = approximatelyEqual(1000, 950, 20);

Hopefully the comments describe the function well enough, so I’ll leave it at that, except for two related notes:

• The line that determines the tolerance uses Java mixed-type arithmetic rules.
• (The original last line of the function uses the Java ternary operator syntax.)