Java Generic Method

Introduction

Here is the syntax for a generic method: 

<type-param-list > ret-type meth-name (param-list ) {

type-param-list is a comma-separated list of type parameters.

For a generic method, the type parameter list precedes the return type. 


// Demonstrate a simple generic method. 
public class Main {

  // Determine if an object is in an array.
  static <T extends Comparable<T>, V extends T> boolean isIn(T x, V[] y) {
    for (int i = 0; i < y.length; i++) {
      if (x.equals(y[i])) {
        return true;
      }/*from w  ww  .  ja va2  s. c  o  m*/
    }
    return false;
  }

  public static void main(String args[]) {
    // Use isIn() on Integers.
    Integer nums[] = { 1, 2, 3, 4, 5 };

    if (isIn(2, nums)) {
      System.out.println("2 is in nums");
    }
    if (!isIn(7, nums)) {
      System.out.println("7 is not in nums");
    }

    // Use isIn() on Strings.
    String strs[] = { "one", "two", "three", "four", "five" };

    if (isIn("two", strs)) {
      System.out.println("two is in strs");
    }
    if (!isIn("seven", strs)) {
      System.out.println("seven is not in strs");
    }
  }
}



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