What does colon represent in java

The colon in Java is used to access parent class members (use super: member name) and define labels (use label name:).

Colon (:) in Java

The role of colon (:) in Java:

The colon in Java is mainly used for two purposes:

1. Access parent class members

• In subclasses Use colons to access data members or methods of the parent class.
• Syntax: super: member name

2. Define the label

• in the code block or A label is placed before a statement to identify the block of code or statement.
• Syntax: Tag name:

Detailed description:

1. Access parent class members

When a subclass needs to access the data members or methods of the parent class, it can use the colon operator. This is useful for subclasses to override parent class methods or access private members of the parent class.

For example:

class Parent {
    private int age;

    public void setAge(int age) {
        this.age = age;
    }
}

class Child extends Parent {
    @Override
    public void setAge(int age) {
        super.setAge(age);  // 访问父类的 setAge() 方法
    }
}

2. Define tags

Tag can specify a name for a code block or statement so that you can jump to that specific one when needed Location. Tags are often used with break or continue statements to control program flow.

For example:

loop: for (int i = 0; i < 10; i++) {
    if (i == 5) {
        break loop;  // 跳出 loop 标签指定的 for 循环
    }
}

Please note that labels must be defined before the code block or statement. Additionally, the label's name must be a valid identifier.

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