{"id":8342,"date":"2024-10-26T08:01:06","date_gmt":"2024-10-26T12:01:06","guid":{"rendered":"https:\/\/springframework.guru\/?p=8342"},"modified":"2024-10-26T08:01:54","modified_gmt":"2024-10-26T12:01:54","slug":"how-to-use-java-if-else-statement","status":"publish","type":"post","link":"https:\/\/springframework.guru\/how-to-use-java-if-else-statement\/","title":{"rendered":"How to Use – Java if else statement"},"content":{"rendered":"\n

The if else<\/code> statement is a fundamental control structures in Java.. This structure evaluates conditions and executes code based on whether those conditions are true<\/code> or false<\/code>. Let\u2019s look at how to use if<\/code>, if else<\/code>, and else if<\/code> statements effectively.<\/p>\n\n\n\n

The Java if Statement<\/h2>\n\n\n\n

An if<\/code> statement evaluates a condition and runs the code block only if the condition is true<\/code>. <\/p>\n\n\n\n

For example:<\/p>\n\n\n\n

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int<\/span> age <\/span>=<\/span> <\/span>18<\/span>;<\/span><\/span>\n<\/span>\nif<\/span> (age <\/span>>=<\/span> <\/span>18<\/span>) {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"You are an adult."<\/span>);<\/span><\/span>\n}<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
In this example, if age<\/code> is 18 or above, the message will print. If not, the if block is skipped and nothing happens.<\/p>\n\n\n\n
The Java if else Statement<\/h2>\n\n\n\n
To add an alternative action when the condition is false<\/code>, use an if-else<\/code> statement:<\/p>\n\n\n\n
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int<\/span> age <\/span>=<\/span> <\/span>16<\/span>;<\/span><\/span>\n<\/span>\nif<\/span> (age <\/span>>=<\/span> <\/span>18<\/span>) {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"You are an adult."<\/span>);<\/span><\/span>\n} <\/span>else<\/span> {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"You are not an adult."<\/span>);<\/span><\/span>\n}<\/span><\/span>\n<\/span>\n-----------------------<\/span>output<\/span>-------------------<\/span><\/span>\nYou are not an adult.<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
In this example the age is 16, which is less than 18, so the first output statement is skipped. Since the first block is skipped, the else<\/code> block is executed. <\/p>\n\n\n\n
The Java if else if<\/code> for Multiple Conditions<\/h3>\n\n\n\n
The previous example was limited to the evaluation of one condition. You can chain multiple conditions using else if<\/code>. This is useful when there are more than two possible outcomes:<\/p>\n\n\n\n
For example:<\/p>\n\n\n\n
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int<\/span> score <\/span>=<\/span> <\/span>85<\/span>;<\/span><\/span>\n<\/span>\nif<\/span> (score <\/span>>=<\/span> <\/span>90<\/span>) {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"Grade: A"<\/span>);<\/span><\/span>\n} <\/span>else<\/span> <\/span>if<\/span> (score <\/span>>=<\/span> <\/span>80<\/span>) {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"Grade: B"<\/span>);<\/span><\/span>\n} <\/span>else<\/span> <\/span>if<\/span> (score <\/span>>=<\/span> <\/span>70<\/span>) {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"Grade: C"<\/span>);<\/span><\/span>\n} <\/span>else<\/span> {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"Grade: D"<\/span>);<\/span><\/span>\n}<\/span><\/span>\n<\/span>\n-----------<\/span>output<\/span>--------------<\/span><\/span>\n<\/span>\nGrade<\/span>:<\/span> B<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
The program checks each condition in sequence, and the first true condition executes. If none of the conditions are true, the else<\/code> block runs.<\/p>\n\n\n\n
Note:<\/strong> Use of an else block is optional. The purpose of the else block is to provide a failsafe if none of the prior conditions are executed. Sometimes you will want to do nothing, or simply log that you encountered an unexpected condition.<\/p>\n\n\n\n
Nested if<\/code> Statements<\/h3>\n\n\n\n
In cases requiring more complex logic, you can nest if<\/code> statements inside each other. However, avoid excessive nesting, is considered a code smell. Excessing nesting produces code that is hard to read, and difficult to maintain. <\/p>\n\n\n\n
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int<\/span> age <\/span>=<\/span> <\/span>22<\/span>;<\/span><\/span>\nboolean<\/span> hasLicense <\/span>=<\/span> <\/span>true<\/span>;<\/span><\/span>\n<\/span>\nif<\/span> (age <\/span>>=<\/span> <\/span>18<\/span>) {<\/span><\/span>\n    <\/span>if<\/span> (hasLicense) {<\/span><\/span>\n        System.out.<\/span>println<\/span>(<\/span>"You can drive."<\/span>);<\/span><\/span>\n    } <\/span>else<\/span> {<\/span><\/span>\n        System.out.<\/span>println<\/span>(<\/span>"You need a license to drive."<\/span>);<\/span><\/span>\n    }<\/span><\/span>\n} <\/span>else<\/span> {<\/span><\/span>\n    System.out.<\/span>println<\/span>(<\/span>"You are too young to drive."<\/span>);<\/span><\/span>\n}<\/span><\/span>\n<\/span>\n-----------<\/span>output<\/span>-----------<\/span><\/span>\n<\/span>\nYou can drive.<\/span><\/span><\/code><\/pre><\/div>\n\n\n\n
Best Practices<\/h3>\n\n\n\n