{"id":6491,"date":"2024-04-21T23:29:02","date_gmt":"2024-04-22T06:29:02","guid":{"rendered":"https:\/\/zentut.com\/java-tutorial\/java-switch\/"},"modified":"2024-04-21T23:29:47","modified_gmt":"2024-04-22T06:29:47","slug":"java-switch","status":"publish","type":"page","link":"https:\/\/www.zentut.com\/java-tutorial\/java-switch\/","title":{"rendered":"Java switch"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to use the Java switch statement to compare a value with multiple values and execute different code based on matches.<\/p>\n\n\n\n

Introduction to the Java switch statement<\/h2>\n\n\n\n

The switch<\/code> statement allows you to evaluate an expression<\/code>, compare its result with multiple possible values, and execute different code blocks based on the match.<\/p>\n\n\n\n

Here’s the syntax of the switch statement:<\/p>\n\n\n

switch<\/span> (expression) {\n    case<\/span> value1:\n        \/\/ Code to execute when expression equals value1<\/span>\n        break<\/span>;\n    case<\/span> value2:\n        \/\/ Code to execute when expression equals value2<\/span>\n        break<\/span>;\n    \/\/ More cases...<\/span>\n    default<\/span>:\n        \/\/ Code to execute when none of the cases match the expression<\/span>\n}<\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
In this syntax:<\/p>\n\n\n\n
    \n
  • expression<\/code>: This is the expression whose value will be compared against the case<\/code> values.<\/li>\n\n\n\n
  • value1<\/code>, value2<\/code>, etc.: These are the possible values that the expression<\/code> can match. You can have multiple case<\/code> labels.<\/li>\n\n\n\n
  • break<\/code>: The break<\/code> statement is used to exit the switch<\/code> block once a match is found. Without break<\/code>, the control will continue to the next case<\/code>, which may lead to unexpected behavior.<\/li>\n<\/ul>\n\n\n\n
    How the switch statement works:<\/p>\n\n\n\n
      \n
    • First, evaluate the expression<\/code>. <\/li>\n\n\n\n
    • Second, compare the results of the expression<\/code> with each case<\/code> label.<\/li>\n\n\n\n
    • Third, execute the code block associated with that case<\/code> label if a match is found.<\/li>\n\n\n\n
    • Finally, if no match is found, and there is a default<\/code> case, execute the code block under the default<\/code> label.<\/li>\n<\/ul>\n\n\n\n
      expression<\/h3>\n\n\n\n
      This is the expression that the switch statement will evaluate and use its result to compare against multiple values.<\/p>\n\n\n\n
      The switch works with the following primitive types:<\/p>\n\n\n\n
        \n
      • byte<\/li>\n\n\n\n
      • sort<\/li>\n\n\n\n
      • int<\/li>\n\n\n\n
      • char<\/li>\n<\/ul>\n\n\n\n
        Besides these primitive types, the switch also supports the wrapper types of these primitive types, the enum type, and the String class. You’ll learn more about these types later.<\/p>\n\n\n\n
        case label<\/h3>\n\n\n\n
        The switch statement may contain one or more case labels:<\/p>\n\n\n
        case<\/span> value:<\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
        In the case label, you specify the value that the expression is compared against. The value in the case label must be a compile-time constant. In other words, it must be a literal or final variable.<\/p>\n\n\n\n
        default case<\/h3>\n\n\n\n
        The default is optional in a switch statement. The switch statement will execute the default case when the expression doesn’t match any values. <\/p>\n\n\n\n
        It’s a good practice to always include a default case.<\/p>\n\n\n\n
        break statement<\/h3>\n\n\n\n
        The break<\/code> statement is used to exit the switch<\/code> block once a match is found. <\/p>\n\n\n\n
        Without break<\/code>, the control will “fall through” to the next case<\/code>, executing all subsequent code blocks until a break<\/code> is encountered or the switch<\/code> block ends.<\/p>\n\n\n\n
        Java switch statement examples<\/h2>\n\n\n\n
        Let’s take some examples of using the Java switch statement.<\/p>\n\n\n\n
        1) Simple Java switch example<\/h3>\n\n\n\n
        The following example illustrates how to use the switch statement to display the day name based on the day number:<\/p>\n\n\n
        public<\/span> class<\/span> App<\/span> <\/span>{\n    public<\/span> static<\/span> void<\/span> main<\/span>(String[] args)<\/span> <\/span>{\n        int<\/span> day = 3<\/span>;\n\n        switch<\/span> (day) {\n            case<\/span> 1<\/span>:\n                System.out.println(\"Sunday\"<\/span>);\n                break<\/span>;\n            case<\/span> 2<\/span>:\n                System.out.println(\"Monday\"<\/span>);\n                break<\/span>;\n            case<\/span> 3<\/span>:\n                System.out.println(\"Tuesday\"<\/span>);\n                break<\/span>;\n            case<\/span> 4<\/span>:\n                System.out.println(\"Wednesday\"<\/span>);\n                break<\/span>;\n            case<\/span> 5<\/span>:\n                System.out.println(\"Thursday\"<\/span>);\n                break<\/span>;\n            case<\/span> 6<\/span>:\n                System.out.println(\"Friday\"<\/span>);\n                break<\/span>;\n            case<\/span> 7<\/span>:\n                System.out.println(\"Saturday\"<\/span>);\n                break<\/span>;\n            default<\/span>:\n                System.out.println(\"Invalid day\"<\/span>);\n        }\n    }\n}<\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
        Output:<\/p>\n\n\n
        Tuesday<\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
        How it works.<\/p>\n\n\n\n
        First, declare the day variable and initialize its value to 3.<\/p>\n\n\n\n
        Second, compare the day with values from 1 to 7 and display the day’s names respectively. If the day is not between 1 and 7, display the message “Invalid day” in the default.<\/p>\n\n\n\n
        The program displays the message “Tuesday” because the day is 3 which matches case 3.<\/p>\n\n\n\n
        2) Using switch statement with fall through example<\/h3>\n\n\n\n
        The following example illustrates how to use the switch statement to display quarter based on the provided month:<\/p>\n\n\n
        public<\/span> class<\/span> App<\/span> <\/span>{\n    public<\/span> static<\/span> void<\/span> main<\/span>(String[] args)<\/span> <\/span>{\n        byte<\/span> month = 5<\/span>;\n        switch<\/span> (month) {\n            case<\/span> 1<\/span>:\n            case<\/span> 2<\/span>:\n            case<\/span> 3<\/span>:\n                System.out.println(\"Quarter 1\"<\/span>);\n                break<\/span>;\n            case<\/span> 4<\/span>:\n            case<\/span> 5<\/span>:\n            case<\/span> 6<\/span>:\n                System.out.println(\"Quarter 2\"<\/span>);\n                break<\/span>;\n            case<\/span> 7<\/span>:\n            case<\/span> 8<\/span>:\n            case<\/span> 9<\/span>:\n                System.out.println(\"Quarter 3\"<\/span>);\n                break<\/span>;\n            case<\/span> 10<\/span>:\n            case<\/span> 11<\/span>:\n            case<\/span> 12<\/span>:\n                System.out.println(\"Quarter 4\"<\/span>);\n                break<\/span>;\n            default<\/span>:\n                System.out.println(\"Invalid month\"<\/span>);\n        }\n    }\n}<\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
        Output:<\/p>\n\n\n
        Quarter 2<\/span><\/code><\/span>Code language:<\/span> Java<\/span> (<\/span>java<\/span>)<\/span><\/small><\/pre>\n\n\n
        The program will print:<\/p>\n\n\n\n
          \n
        • Quarter 1 if the month is 1, 2, and 3. <\/li>\n\n\n\n
        • Quarter 2 if the month is 4, 5, and 6.<\/li>\n\n\n\n
        • Quarter 3 if the month is 7, 8, and 9.<\/li>\n\n\n\n
        • Quarter 4 if the month is 10, 11, and 12.<\/li>\n<\/ul>\n\n\n\n
          In this program, you can see that case<\/code> blocks 1, 2, and 3, for example, do not have break<\/code> statements. This means that if month<\/code> is 1, the code under “Quarter 1” is executed, and then it continues to execute the code under “Quarter 2” and “Quarter 3” as well. This behavior continues until a break<\/code> statement is encountered or until the switch<\/code> block ends.<\/p>\n\n\n\n
          As you can see, we intentionally use “fall through” to group multiple months into the same quarter.<\/p>\n\n\n\n
          Summary<\/h2>\n\n\n\n
            \n
          • Java switch statement to compare a value with multiple values and execute different blocks of code based on matches.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
            In this tutorial, you will learn how to use the Java switch statement to compare a value with multiple values and execute different code based on matches.<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":2190,"menu_order":16,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-6491","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/pages\/6491","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/comments?post=6491"}],"version-history":[{"count":2,"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/pages\/6491\/revisions"}],"predecessor-version":[{"id":6493,"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/pages\/6491\/revisions\/6493"}],"up":[{"embeddable":true,"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/pages\/2190"}],"wp:attachment":[{"href":"https:\/\/www.zentut.com\/wp-json\/wp\/v2\/media?parent=6491"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}