Question

I need to use “hypot” method in my Android game however eclipse says there is no such a method. Here is my code:

import java.lang.Math;//in the top of my file
float distance = hypot(xdif, ydif);//somewhere in the code

Answer 1

Firstly, you don’t need to import types in java.lang at all. There’s an implicit import java.lang.*; already. But importing a type just makes that type available by its simple name; it doesn’t mean you can refer to the methods without specifying the type. You have three options:

• Use a static import for each function you want:

  import static java.lang.Math.hypot;
  // etc
  

• Use a wildcard static import:

  import static java.lang.Math.*;
  

• Explicitly refer to the static method:

  // See note below
  float distance = Math.hypot(xdif, ydif);
  

Also note that hypot returns double, not float – so you either need to cast, or make distance a double:

// Either this...
double distance = hypot(xdif, ydif);

// Or this...
float distance = (float) hypot(xdif, ydif);