What is the default value of local variables in Java?

Local variables can be declared in method, code blocks, constructors, etc. in Java. When program control enters a method, code block, constructor, etc., local variables are created, and when program control leaves a method, code block, constructor, etc., local variables are destroyed. In Java, local variables do not have default values ​​. This means that they can be declared and assigned before the variable is first used, otherwise, the compiler will throw an error .

Example

public class LocalVariableTest {
   public void print() {
      int num;
      System.out.println("The number is : " + num);
   }
   public static void main(String args[]) {
      LocalVariableTest obj = new LocalVariableTest();
      obj.print();
   }
}

In the above program, a local variable num cannot be initialized to a value, so an error will be generated, similar to “variable num might not have been initialized”.

Output

LocalVariableTest.java:4: error: variable num might not have been initialized
 System.out.println("The number is : " + num);
^
1 error

Example

is translated into Chinese as:

Example

public class LocalVariableTest {
   public void print() {
      int num = 100;
      System.out.println("The number is : " + num);
   }
   public static void main(String args[]) {
      LocalVariableTest obj = new LocalVariableTest();
      obj.print();
   }
}

In the above program , a local variable num can be initialized to a value of 100

output

The number is : 100

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