Java – Convert int[] to Integer[] example
Examples show you how to convert between int[]
and its’ wrapper class Integer[]
.
1. Convert int[] to Integer[]
public static Integer[] toObject(int[] intArray) {
Integer[] result = new Integer[intArray.length];
for (int i = 0; i < intArray.length; i++) {
result[i] = Integer.valueOf(intArray[i]);
}
return result;
}
2. Convert Integer[] to int[]
public static int[] toPrimitive(Integer[] IntegerArray) {
int[] result = new int[IntegerArray.length];
for (int i = 0; i < IntegerArray.length; i++) {
result[i] = IntegerArray[i].intValue();
}
return result;
}
The theory is simple, create a new array, and dump the old value inside.
1. Full Example
Review a full example to show you how it works.
ArrayConvertExample.java
package com.mkyong.test;
public class ArrayConvertExample {
public static void main(String[] args) {
int[] obj = new int[] { 1, 2, 3 };
Integer[] newObj = toObject(obj);
System.out.println("Test toObject() - int -> Integer");
for (Integer temp : newObj) {
System.out.println(temp);
}
Integer[] obj2 = new Integer[] { 4, 5, 6 };
int[] newObj2 = toPrimitive(obj2);
System.out.println("Test toPrimitive() - Integer -> int");
for (int temp : newObj2) {
System.out.println(temp);
}
}
// Convert int[] to Integer[]
public static Integer[] toObject(int[] intArray) {
Integer[] result = new Integer[intArray.length];
for (int i = 0; i < intArray.length; i++) {
result[i] = Integer.valueOf(intArray[i]);
}
return result;
}
// Convert Integer[] to int[]
public static int[] toPrimitive(Integer[] IntegerArray) {
int[] result = new int[IntegerArray.length];
for (int i = 0; i < IntegerArray.length; i++) {
result[i] = IntegerArray[i].intValue();
}
return result;
}
}
Output
Test toObject() - int -> Integer
1
2
3
Test toPrimitive() - Integer -> int
4
5
6
2. ArrayUtils Example
To save you time, uses the ArrayUtils
class from the Apache common library, it does the same thing.
ArrayConvertExample.java
package com.mkyong.test;
import org.apache.commons.lang3.ArrayUtils;
public class ArrayConvertExample {
public static void main(String[] args) {
int[] obj = new int[] { 1, 2, 3 };
Integer[] newObj = ArrayUtils.toObject(obj);
System.out.println("Test toObject() - int -> Integer");
for (Integer temp : newObj) {
System.out.println(temp);
}
Integer[] obj2 = new Integer[] { 4, 5, 6 };
int[] newObj2 = ArrayUtils.toPrimitive(obj2);
System.out.println("Test toPrimitive() - Integer -> int");
for (int temp : newObj2) {
System.out.println(temp);
}
}
Test toObject() - int -> Integer
1
2
3
Test toPrimitive() - Integer -> int
4
5
6
Hi! thank you so much mkyong, you helped me a lot through hard times and you are the only reason my parents still love me. keep up the good work!
how to write xml parse in java and display in html….. plz reply