Arrays.asList(<Array of Integer>).indexOf(<target int>)
Where Arrays.asList(<Array of Integer>) returns a fixed-size list backed by the specified array. indexOf(<target int>) returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. Please notice that <Array of Integer> can be Integer[], not int[]; because int is a primitive types, a special data types built into the language; they are not objects created from a class.
Example:
package javatestarray; import java.util.Arrays; /** * @web http://java-buddy.blogspot.com/ */ public class JavaTestArray { final static int[] Array_int = {1, 2, 3, 4, 5}; final static Integer[] Array_Integer = {1, 2, 3, 4, 5}; public static void main(String[] args) { int indexIn_Array_int = Arrays.asList(Array_int).indexOf(3); System.out.println("indexIn_Array_int = " + indexIn_Array_int); //not work! -1 will be returned. int indexIn_Array_Integer = Arrays.asList(Array_Integer).indexOf(3); System.out.println("indexIn_Array_Integer = " + indexIn_Array_Integer); //2 will be returned } }
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