Java Programming/Keywords/boolean
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boolean is a keyword which designates the boolean primitive type. There are only two possible boolean values: true and false . The default value for boolean fields is false .
The following is a declaration of a private boolean field named initialized, and its use in a method named synchronizeConnection.
Example
Code section 1: Connection synchronization.
privatebooleaninitialized=false; publicvoidsynchronizeConnection(){ if(!initialized){ connection=connect(); initialized=true; } }
The previous code only creates a connection once (at the first method call). Note that there is no automatic conversion between integer types (such as int ) to boolean as is possible in some languages like C. Instead, one must use an equivalent expression such as (i != 0) which evaluates to true if i is not zero.