Example :<\/strong><\/span><\/p>\nublic class IntegerDemo {\r\n\r\n\tpublic static void main(String[] args) {\r\n\r\n\t\tint n1 = Integer.parseInt(\"8\");\r\n\t\t\/\/ int n2 = Integer.parseInt(\"OCA\"); This generates NumberFormatException.\r\n\r\n\t\tSystem.out.println(n1);\/\/prints 8\r\n\r\n\t}\r\n}\r\n<\/pre>\ntoBinaryString, toOctalString, toHexString<\/h4>\n
public static String toHexString(int i)<\/strong>
\nIt returns a string representation of the integer argument as an unsigned integer in base 16.<\/p>\npublic static String toOctalString(int i)<\/strong>
\nIt returns a string representation of the integer argument as an unsigned integer in base 8.<\/p>\npublic static String toBinaryString(int i)<\/strong>
\nIt returns a string representation of the integer argument as an unsigned integer in base 2.
\nExample :<\/strong><\/span><\/p>\npublic class IntegerDemo {\r\n\r\n\tpublic static void main(String[] args) {\r\n\r\n\t\tString s1 = Integer.toHexString(8);\r\n\t\tString s2 = Integer.toOctalString(8);\r\n\t\tString s3 = Integer.toBinaryString(8);\r\n\t\tSystem.out.println(s1 + \" \" + s2 + \" \" + s3); \/\/ prints 8 10 1000\r\n\t}\r\n\r\n}\r\n<\/pre>\nvalueOf,byteValue, doubleValue, floatValue,intValue,longValue<\/h4>\n
public static Integer valueOf(int i)<\/strong>
\nIt returns an Integer instance representing the specified int value.
\npublic byte byteValue()<\/strong>
\nIt returns the value of this Integer as a byte after a narrowing primitive conversion.
\npublic double doubleValue()<\/strong>
\nIt returns the value of this Integer as a double after a widening primitive conversion.
\npublic float floatValue()<\/strong>
\nIt returns the value of this Integer as a float after a widening primitive conversion.
\npublic int intValue()<\/strong>
\nIt returns the value of this Integer as an int.
\npublic long longValue()<\/strong>
\nIt returns the value of this Integer as a long after a widening primitive conversion.
\nExample :<\/strong><\/span><\/p>\npublic class IntegerDemo {\r\n\r\n\tpublic static void main(String[] args) {\r\n\r\n\t\tInteger in = Integer.valueOf(8);\r\n\t\tbyte b = in.byteValue();\r\n\t\tint i = in.intValue();\r\n\t\tlong l = in.longValue();\r\n\t\tfloat f = in.floatValue();\r\n\t\tdouble d = in.doubleValue();\r\n\t\tSystem.out.println(in+\" \"+b+\" \"+i+\" \"+l+\" \"+f+\" \"+d);\/\/It prints 8 8 8 8 8.0 8.0\r\n\t\t\r\n\t}\r\n\r\n}\r\n<\/pre>\n<\/span>Autoboxing and unboxing<\/span><\/h3>\n\t\tList<Integer> li = new ArrayList<Integer>();\r\n\t\tli.add(8);\/\/ line 1\r\n\t\tli.add(new Integer(5));\/\/ line 2\r\n\t\tint n = li.get(1);\/\/ line 3\r\n<\/pre>\n
\n- At line1 you just typed 8 primitive value java will create Integer object and stores in ArrayList object, this process is called Autoboxing.<\/li>\n
- At line2 you are creating the object. No Autoboxing here.<\/li>\n
- At line3 get method returns Integer object and that is converted into primitive int value when it is assigning to int variable,this process is called Auto unboxing.<\/li>\n<\/ul>\n
<\/span>Double<\/span><\/h2>\nHere are the some important points about the Double class:<\/p>\n
\n- Double class is in java.lang package since Java 1.0 version.<\/li>\n
- Number class is the super class of Double.<\/li>\n
- It implements Comparable,Serializable interfaces.<\/li>\n
- It is a immutable class.<\/li>\n
- The Double class wraps a value of the primitive type double in an object. An object of type Double contains a single field whose type is double.<\/li>\n
- In addition, this class provides several methods for converting an double to a String and a String to an double, as well as other constants and methods useful when dealing with an double.<\/li>\n<\/ul>\n
<\/span>Creating Double Object<\/span><\/h3>\nDouble class has two constructors.<\/p>\n
![\"OCPJP](\"https:\/\/www.whizlabs.com\/blog\/wp-content\/uploads\/2024\/05\/free_test.jpg\")
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