{"id":1146,"date":"2022-02-24T18:44:28","date_gmt":"2022-02-24T18:44:28","guid":{"rendered":"https:\/\/mdr.foobrdigital.com\/?p=1146"},"modified":"2022-02-24T18:44:28","modified_gmt":"2022-02-24T18:44:28","slug":"variables-and-literals","status":"publish","type":"post","link":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/2022\/02\/24\/variables-and-literals\/","title":{"rendered":"Variables and Literals"},"content":{"rendered":"\n

In this tutorial, we will learn about Java variables and literals with the help of examples.<\/p>\n\n\n\n

Java Variables<\/h2>\n\n\n\n

A variable is a location in memory (storage area) to hold data.<\/p>\n\n\n\n

To indicate the storage area, each variable should be given a unique name (identifier). Learn more about\u00a0Java identifiers.<\/p>\n\n\n\n

\n\n\n\n

Create Variables in Java<\/h3>\n\n\n\n

Here’s how we create a variable in Java,<\/p>\n\n\n\n

int speedLimit = 80;<\/code><\/pre>\n\n\n\n
Here, speedLimit<\/var> is a variable of int<\/var> data type and we have assigned value 80<\/strong> to it.<\/p>\n\n\n\n
The int data type suggests that the variable can only hold integers. To learn more, visit\u00a0Java data types.<\/p>\n\n\n\n
In the example, we have assigned value to the variable during declaration. However, it’s not mandatory.<\/p>\n\n\n\n
You can declare variables and assign variables separately. For example,<\/p>\n\n\n\n
int speedLimit;\nspeedLimit = 80;<\/code><\/pre>\n\n\n\n
Note<\/strong>: Java is a statically-typed language. It means that all variables must be declared before they can be used.<\/p>\n\n\n\n
\n\n\n\n
Change values of variables<\/h3>\n\n\n\n
The value of a variable can be changed in the program, hence the name variable<\/strong>. For example,<\/p>\n\n\n\n
int speedLimit = 80;\n... .. ...\nspeedLimit = 90; <\/code><\/pre>\n\n\n\n
Here, initially, the value of speedLimit<\/var> is 80<\/strong>. Later, we changed it to 90<\/strong>.<\/p>\n\n\n\n
However, we cannot change the data type of a variable in Java within the same scope.<\/p>\n\n\n\n
What is the variable scope?<\/p>\n\n\n\n
Don’t worry about it for now. Just remember that we can’t do something like this:<\/p>\n\n\n\n
int speedLimit = 80;\n... .. ...\nfloat speedLimit;<\/code><\/pre>\n\n\n\n
<\/p>\n\n\n\n
\n\n\n\n
Rules for Naming Variables in Java<\/h2>\n\n\n\n
Java programming language has its own set of rules and conventions for naming variables. Here’s what you need to know:<\/p>\n\n\n\n
  • Java is case sensitive. Hence,\u00a0age<\/var>\u00a0and\u00a0AGE<\/var>\u00a0are two different variables. For example,
    \u00a0<\/li><\/ul>\n\n\n\n
    int age = 24;\n int AGE = 25;\n System.out.println(age); \n\/\/ prints 24 System.out.println(AGE); \n\/\/ prints 25<\/code><\/pre>\n\n\n\n
    <\/p>\n\n\n\n
    • Variables must start with either a\u00a0letter<\/strong>\u00a0or an\u00a0underscore, _<\/strong>\u00a0or a\u00a0dollar, $<\/strong>\u00a0sign. For example,
      <\/li><\/ul>\n\n\n\n
      int age; \n\/\/ valid name and good practice int _age; \n\/\/ valid but bad practice int $age; \n\/\/ valid but bad practice<\/code><\/pre>\n\n\n\n
      • Variable names cannot start with numbers. For example,<\/li><\/ul>\n\n\n\n
         int 1age; \n\/\/ invalid variables<\/code><\/pre>\n\n\n\n
        • Variable names can’t use whitespace. For example,<\/li><\/ul>\n\n\n\n
          int my age; <\/code>\n\/\/ invalid variables<\/code><\/code><\/pre>\n\n\n\n

          Here, is we need to use variable names having more than one word, use all lowercase letters for the first word and capitalize the first letter of each subsequent word. For example,\u00a0myAge<\/var>.<\/p>\n\n\n\n
          When creating variables, choose a name that makes sense. For example,\u00a0score<\/var>,\u00a0number<\/var>,\u00a0level<\/var>\u00a0makes more sense than variable names such as\u00a0s<\/var>,\u00a0n<\/var>, and\u00a0l<\/var>.<\/p>\n\n\n\n
          If you choose one-word variable names, use all lowercase letters. For example, it’s better to use\u00a0speed<\/var>\u00a0rather than\u00a0SPEED<\/var>, or\u00a0sPEED<\/var>.<\/p>\n\n\n\n
          \n\n\n\n
          There are 4 types of variables in Java programming language:<\/p>\n\n\n\n
          • Instance Variables (Non-Static Fields)<\/li>
          • Class Variables (Static Fields)<\/li>
          • Local Variables<\/li>
          • Parameters<\/li><\/ul>\n\n\n\n
            If you are interested to learn more about it now, visit\u00a0Java Variable Types.<\/p>\n\n\n\n
            \n\n\n\n
            Java literals<\/h2>\n\n\n\n
            Literals are data used for representing fixed values. They can be used directly in the code. For example,<\/p>\n\n\n\n
            int a = 1;\nfloat b = 2.5;\nchar c = 'F';<\/code><\/pre>\n\n\n\n
            Here, 1<\/code>, 2.5<\/code>, and 'F'<\/code> are literals.<\/p>\n\n\n\n
            Here are different types of literals in Java.<\/p>\n\n\n\n
            1. Boolean Literals<\/h3>\n\n\n\n
            In Java, boolean literals are used to initialize boolean data types. They can store two values: true and false. For example,<\/p>\n\n\n\n
            boolean flag1 = false;\nboolean flag2 = true;<\/code><\/pre>\n\n\n\n
            Here, false<\/code> and true<\/code> are two boolean literals.<\/p>\n\n\n\n
            \n\n\n\n
            2. Integer Literals<\/h3>\n\n\n\n
            An integer literal is a numeric value(associated with numbers) without any fractional or exponential part. There are 4 types of integer literals in Java:<\/p>\n\n\n\n
            1. binary (base 2)<\/li>
            2. decimal (base 10)<\/li>
            3. octal (base 8)<\/li>
            4. hexadecimal (base 16)<\/li><\/ol>\n\n\n\n
              For example:<\/p>\n\n\n\n
              \/\/ binary\nint binaryNumber = 0b10010;\n\/\/ octal \nint octalNumber = 027;\n\n\/\/ decimal\nint decNumber = 34;\n\n\/\/ hexadecimal \nint hexNumber = 0x2F; \/\/ 0x represents hexadecimal\n\/\/ binary\nint binNumber = 0b10010; \/\/ 0b represents binary<\/code><\/pre>\n\n\n\n
              In Java, binary starts with 0b<\/strong>, octal starts with 0<\/strong>, and hexadecimal starts with 0x<\/strong>.<\/p>\n\n\n\n
              Note<\/strong>: Integer literals are used to initialize variables of integer types like byte<\/code>, short<\/code>, int<\/code>, and long<\/code>.<\/p>\n\n\n\n
              \n\n\n\n
              3. Floating-point Literals<\/h3>\n\n\n\n
              A floating-point literal is a numeric literal that has either a fractional form or an exponential form. For example,<\/p>\n\n\n\n
              class Main {\n  public static void main(String[] args) {\n    \t\n    double myDouble = 3.4;\n    float myFloat = 3.4F;\n \n    \/\/ 3.445*10^2\n    double myDoubleScientific = 3.445e2;\n\n    System.out.println(myDouble);  \/\/ prints 3.4\n    System.out.println(myFloat);    \/\/ prints 3.4\n    System.out.println(myDoubleScientific);   \/\/ prints 344.5\n  }\n}<\/code><\/pre>\n\n\n\n
              Note<\/strong>: The floating-point literals are used to initialize float<\/code> and double<\/code> type variables.<\/p>\n\n\n\n
              \n\n\n\n
              4. Character Literals<\/h3>\n\n\n\n
              Character literals are unicode character enclosed inside single quotes. For example,<\/p>\n\n\n\n
              char letter = 'a';<\/code><\/pre>\n\n\n\n
              Here, a<\/code> is the character literal.<\/p>\n\n\n\n
              We can also use escape sequences as character literals. For example, \\b<\/strong> (backspace), \\t<\/strong> (tab), \\n<\/strong> (new line), etc.<\/p>\n\n\n\n
              \n\n\n\n
              5. String literals<\/h3>\n\n\n\n
              A string literal is a sequence of characters enclosed inside double-quotes. For example,<\/p>\n\n\n\n
              String str1 = \"Java Programming\";\nString str2 = \"Programiz\";<\/code><\/pre>\n\n\n\n
              Here, Java Programming<\/code> and Programiz<\/code> are two string literals.<\/p>\n","protected":false},"excerpt":{"rendered":"
              In this tutorial, we will learn about Java variables and literals with the help of examples. Java Variables A variable is a location in memory (storage area) to hold data. To indicate the storage area, each variable should be given a unique name (identifier). Learn more about\u00a0Java identifiers. Create Variables in Java Here’s how we […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[290],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1146"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=1146"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/1146\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=1146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=1146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=1146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}