{"id":40,"date":"2019-01-15T10:54:35","date_gmt":"2019-01-15T10:54:35","guid":{"rendered":"https:\/\/kindsonthegenius.com\/java\/?p=40"},"modified":"2019-03-02T04:35:24","modified_gmt":"2019-03-02T04:35:24","slug":"07java-basic-data-types","status":"publish","type":"post","link":"https:\/\/kindsonthegenius.com\/java\/07java-basic-data-types\/","title":{"rendered":"Java – Basic Data Types"},"content":{"rendered":"\n
  1. Introduction to Data Types<\/a><\/li>
  2. Primitive Data Types<\/a><\/li>
  3. Reference Data Types<\/a><\/li>
  4. Literals in Java<\/a><\/li>
  5. Escape Sequences<\/a><\/li><\/ol>\n\n\n\n

    <\/p>\n\n\n\n

    1. Introduction to Data Types<\/strong><\/h4>\n\n\n\n

    First of all, you should remember that Java is a statically typed languages. For this reason, variables must be declared before use. Variable declaration allocated memory for the variable.<\/p>\n\n\n\n

    Amount of space allocated depends of the data type. Therefore, we would examine Java basic data types. We have two types of data in Java:<\/p>\n\n\n\n

    • Primitive Data Type<\/li>
    • Reference Data Type<\/li><\/ul>\n\n\n\n

      <\/p>\n\n\n\n

      2. Primitive Data Type<\/strong><\/h4>\n\n\n\n

      We have eight of them. They are byte, short, long, float, double, char and boolean.<\/p>\n\n\n\n

      byte<\/strong><\/p>\n\n\n\n

      • 8 bit signed integer<\/li>
      • Ranges from -128 to 127<\/li>
      • Default value of 0<\/li>
      • For example: byte x = 20, byte y = -5<\/li><\/ul>\n\n\n\n

        short<\/strong><\/p>\n\n\n\n

        • 16 bit signed integer<\/li>
        • Ranges from -32,768 to 32,767<\/li>
        • Default value of 0<\/li>
        • For example: short a = 20,000, short b = -12,434<\/li><\/ul>\n\n\n\n

          int<\/strong><\/p>\n\n\n\n

          • 32 singed integer<\/li>
          • Ranges from -2,147,483,648 to 2,147,483,648 <\/li>
          • Default value of 0<\/li>
          • For example: int i = 300000, int j = -574800<\/li>
          • Generally used for integers <\/li><\/ul>\n\n\n\n

            long<\/strong><\/p>\n\n\n\n

            • 64 bit signed integer values<\/li>
            • Ranges from -263<\/sup> to 263<\/sup> – 1<\/li>
            • Used when very large value is needed<\/li>
            • Default value of 0L<\/li>
            • For example: long x = 200000L; long y = -100000L<\/li><\/ul>\n\n\n\n

              float<\/strong><\/p>\n\n\n\n

              • 32 bit floating point numbers<\/li>
              • Default value of 0.0f<\/li>
              • Not generally used<\/li>
              • Lacks precision relative to double<\/li>
              • For example: float fnum = 0.01f; float fnum2 = 21.840f<\/li><\/ul>\n\n\n\n

                double<\/strong><\/p>\n\n\n\n

                • 64 bit floating point numbers<\/li>
                • Has better precision than float<\/li>
                • A preferred type for decimals<\/li>
                • Default value of 0.0d<\/li>
                • For example: double mydouble = 47.02984; double d = 0.034d<\/li><\/ul>\n\n\n\n

                  char<\/strong><\/p>\n\n\n\n

                  • A single 16 bit unicode character<\/li>
                  • Ranges from ‘\\u0000’ (0) to ‘\\uffff’ (65,535)<\/li>
                  • Stores a single character<\/li>
                  • For exampe: char a = ‘a’; char grade = ‘B’<\/li><\/ul>\n\n\n\n

                    boolean<\/strong><\/p>\n\n\n\n

                    • A single bit data type<\/li>
                    • Has only two values: true or false (1 and 0)<\/li>
                    • Default value of false<\/li>
                    • For example: boolean tall = true<\/li><\/ul>\n\n\n\n

                      <\/p>\n\n\n\n

                      3. Reference Data Types<\/strong><\/h4>\n\n\n\n

                      Reference types are used to access objects. Therefore, they are created using constructors. Note the following about reference types:<\/p>\n\n\n\n

                      • Class objects are declared as reference types<\/li>
                      • Arrays are also reference types<\/li>
                      • Default value of null<\/li>
                      • Reference variable can be used to refer to any object of the declared type<\/li>
                      • For example: Vehicle vehicle = new Vehicle (“Camry”);<\/li><\/ul>\n\n\n\n

                        <\/p>\n\n\n\n

                        4. Literals in Java<\/strong><\/h4>\n\n\n\n

                        \t\tchar<\/span> grade =<\/span> 'A'<\/span>;<\/span>\n\t\tbyte<\/span> b =<\/span> 20<\/span>;<\/span>\n\t\tboolean<\/span> rich =<\/span> true<\/span>;<\/span>\n<\/pre><\/div><\/p>\n\n\n\n
                        Here, ‘A’, 20 and true are all literals.<\/p>\n\n\n\n
                        Furthermore, byte, int, long and short can be express in decimal,  octal or hexadecimal<\/p>\n\n\n\n
                        • decimal is base 10<\/li>
                        • octal is base 8<\/li>
                        • hexadecimal is base 16<\/li><\/ul>\n\n\n\n
                          The following prefix rules applies:<\/p>\n\n\n\n
                          • hexadecimal literals are prefixed with 0x<\/li>
                          • octal literals are prefixed with 0<\/li><\/ul>\n\n\n\n
                            Example is given below:<\/p>\n\n\n\n
                             int<\/span> decimalval =<\/span> 200<\/span>;<\/span> <\/pre><\/div><\/p>\n\n\n
                            \n
                            int<\/span> octalval =<\/span> 0200<\/span>;<\/span> <\/pre>\n<\/div>\n
                            \n
                            int<\/span> hexval =<\/span> 0x128F<\/span>;<\/span> <\/pre>\n<\/div>\n\n\n
                            String Literals<\/strong><\/p>\n\n\n\n
                            String literals are enclosed in double quotes. For example:<\/p>\n\n\n\n
                            • “The Tech Pro<\/li>
                            • “Java”<\/li><\/ul>\n\n\n\n
                              Also note that string literals can be assigned to string variables. We would learn this in subsequent tutorials.<\/p>\n\n\n\n
                              5. Escape Sequences  in Java<\/strong><\/h4>\n\n\n\n
                              Used to control display of strings. Note list of escape sequences below<\/p>\n\n\n\n
                              Sequence<\/th>What it Represents<\/th><\/tr>
                              \\n<\/td>New line (0x0a)<\/td><\/tr>
                              \\r<\/td>Carriage return (0x0d)<\/td><\/tr>
                              \\f<\/td>Formfeed (0x0c)<\/td><\/tr>
                              \\b<\/td>Backspace (0x08)<\/td><\/tr>
                              \\s<\/td>Space  (0x20)<\/td><\/tr>
                              \\t<\/td>tab<\/td><\/tr>
                              \\”<\/td>Double quotes<\/td><\/tr>
                              \\’<\/td>Single quote<\/td><\/tr>
                              \\\\<\/td>backslash<\/td><\/tr>
                              \\ddd<\/td>Octal character (ddd)<\/td><\/tr>
                              \\uxxxx<\/td>Hex UNICODE character (xxxx)<\/td><\/tr><\/tbody><\/table>\n","protected":false},"excerpt":{"rendered":"
                              Introduction to Data Types Primitive Data Types Reference Data Types Literals in Java Escape Sequences 1. Introduction to Data Types First of all, you should remember that Java … <\/p>\n","protected":false},"author":395,"featured_media":42,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-40","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java-tutorial"],"_links":{"self":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/40","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/users\/395"}],"replies":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/comments?post=40"}],"version-history":[{"count":2,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/40\/revisions"}],"predecessor-version":[{"id":43,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/posts\/40\/revisions\/43"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/media\/42"}],"wp:attachment":[{"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/media?parent=40"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/categories?post=40"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kindsonthegenius.com\/java\/wp-json\/wp\/v2\/tags?post=40"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}