java lang Integer Class | Integer class methods in Java
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java.lang.Integer Class
Integer Class in Java
The Integer class wraps the value of primitive data type int into Integer object. An object of type Integer contains a single field whose type is int. In other words the wrapper classes create objects for primitive data types. The wrapper classes are Boolean, Byte, Character, Short, Integer, Float, Long and Double.
Java Integer Methods or Integer class methods in Java
Java Integer class or Java wrapper class Integer provides several useful methods for converting a int to a String and a String to a int, as well as other constants and methods dealing with int. The various Java Integer methods are as follows :
| Return Type | Method | Description |
|---|---|---|
| static int | bitCount() | It returns the number of 1-bits in the 2's complement binary representation of the specified int value. |
| byte | byteValue() | It converts the given number into a primitive byte type and returns the value of integer object as byte. |
| Static int | compare() | It compares two int values numerically and returns the result in integer equivalent. |
| Int | compareTo() | It compares two integer objects numerically and returns the result as -1, 0 or 1. |
| static int | compareUnsigned() | It compares two integer objects numerically treating the values as unsigned and returns the result as -1, 0 or 1. |
| static Integer | decode() | It decodes a String object into an Integer value. |
| static int | divideUnsigned() | It returns the unsigned quotient of dividing the first argument by the second argument where each argument and the result is interpreted as an unsigned value. |
| double | doubleValue() | It converts the given Integer value and returns the result as a double equivalent. |
| boolean | equals() | It compares the value of the parameter to the value of the current Integer object and returns boolean ( True or False ). |
| float | floatValue() | It converts the given Integer value and returns the result as a float equivalent. |
| Static Integer | getInteger() | It determines the integer value of the system property with the specified name. |
| static int | hashCode() | It returns a hash code for the given Integer. |
| static int | highestOneBit() | It returns int value with at most a single one-bit, in the position of the highest-order leftmost one-bit in the specified int value. |
| static int | lowestOneBit() | It eturns int value with at most a single one-bit, in the position of the lowest-order rightmost one-bit in the specified int value. |
| static int | max() | It returns the maximum value amongst the two method argument. |
| static int | min() | It returns the minimum value amongst the two method argument. |
| int | intValue() | It returns the value of the specified number as an int. |
| long | longValue() | It returns the value of the specified long object as long equivalent. |
| static int | numberOfLeadingZeros() | It returns the total number of zero bits preceding the highest-order leftmost one-bit in the 2's complement binary representation of the specified int value. |
| static int | numberOfTrailingZeros() | It returns the total number of zero bits following the lowest-order rightmost one-bit in the 2's complement binary representation of the specified int value. |
| static int | parseInt() | It parses the String argument as a signed decimal Integer object. |
| static int | parseUnsignedInt() | It parses the String argument as an unsigned decimal Integer object. |
| static int | remainderUnsigned() | It returns the unsigned remainder from dividing the first argument by the second argument where each argument and the result is interpreted as an unsigned value. |
| static int | reverse() | It returns the value obtained by reversing the order of the bits in the 2's complement binary representation of the specified int value. |
| static int | reverseBytes() | It returns the value obtained by reversing the order of the bytes in the 2's complement binary representation of the specified int value. |
| static int | rotateLeft() | It returns the value obtained by rotating the 2's complement binary representation of the specified int value left by the specified number of bits. |
| static int | rotateRight() | It returns the value obtained by rotating the 2's complement binary representation of the specified int value right by the specified number of bits. |
| short | shortValue() | It returns the value of this Integer as a short type after a primitive conversion. |
| static int | signum() | It returns the signum function of the specified int value. |
| static int | sum() | It returns the sum by adding two integers together as per the + operator. |
| static String | toBinaryString() | It returns a string representation of the integer argument as an unsigned integer in binary base 2. |
| static String | toHexString() | It returns a string representation of the integer argument as an unsigned integer in binary base 16. |
| static String | toOctalString() | It returns a string representation of the integer argument as an unsigned integer in binary base 8. |
| String | toString() | It returns a String object representing the value of the Number Object. |
| static String | toUnsignedString() | It converts the argument to a long by an unsigned conversion. |
| static long | toUnsignedLong() | It returns a string representation of the argument as an unsigned decimal value. |
| static Integer | valueOf() | It returns the relevant Integer Object holding the value of the argument passed. |
java.lang.Integer Class Example
/* Java Integer Class Example Save with file name IntegerExample.java */public class IntegerExample{ public static void main(String args[]) { //JAVA INTEGER DECLARATION Integer b; //MEMORY ALLOCATION FOR JAVA INTEGER b = new Integer(101); //JAVA INTEGER CLASS OUTPUT System.out.println("Java Integer Class Example"); //RETURNS byte PRIMITIVE DATA TYPE System.out.println("byte Value is : "+ b.byteValue()); //RETURNS short PRIMITIVE DATA TYPE System.out.println("short Value is : "+ b.shortValue()); //RETURNS double PRIMITIVE DATA TYPE System.out.println("double Value is : "+ b.doubleValue()); //RETURNS float PRIMITIVE DATA TYPE System.out.println("float Value is : "+ b.floatValue()); //RETURNS int PRIMITIVE DATA TYPE System.out.println("int Value is : "+ b.intValue()); //RETURNS long PRIMITIVE DATA TYPE System.out.println("long Value is : "+ b.longValue()); }} |
java.lang.Integer Class Example 2
/* Java Integer Class Example 2 Save with file name IntegerExample2.java */public class IntegerExample2{ public static void main(String args[]) { //JAVA INTEGER DECLARATION Integer b, b2; //MEMORY ALLOCATION FOR JAVA INTEGER b = new Integer(101); b2 = new Integer("102"); //JAVA INTEGER CLASS OUTPUT System.out.println("Java Integer Class Example 2"); System.out.println("b Value is : "+ b.intValue()); System.out.println("b2 Value is : "+ b2.intValue()); System.out.println("b compareTo b2 : "+ b.compareTo(b2)); System.out.println("b equals b2 : "+ b.equals(b2)); }} |
Following Java Integer class example you can learn how to use static methods of Java Integer Class. If you use static methods you need not to create the class instance. You can call static methods using the class name as reference.
java.lang.Integer Class Example 3
/* Java Integer Class Example 3 Save with file name IntegerExample3.java */public class IntegerExample3{ public static void main(String args[]) { //INTEGER CLASS STATIC METHODS USAGE System.out.println("Java Integer Class Example 3"); //RETURN Java Integer OBJECT WITH THE SPECIFIED PRIMITIVE int DATA TYPE System.out.println("valueOf : "+ Integer.valueOf(101)); //RETURN Integer OBJECT WITH THE SPECIFIED //PRIMITIVE int DATA TYPE AS String System.out.println("valueOf : "+ Integer.valueOf("103")); //RETURN PRIMITIVE int DATA TYPE WITH THE SPECIFIED //PRIMITIVE int DATA TYPE AS String System.out.println("parseInt : "+ Integer.parseInt("105")); }} |