isinstance

類class isInstance()方法 (Class class isInstance() method)

• isInstance() method is available in java.lang package.

  isInstance()方法在java.lang包中可用。

• isInstance() method is used to check whether the given object is an instance with the object denoted by this Class or not.

  isInstance()方法用于檢查給定對象是否是具有此Class表示的對象的實例。

• isInstance() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  isInstance()方法是一種非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。

• isInstance() method does not throw an exception at the time of checking the given object is assignment compatible with other objects or not.

  在檢查給定對象是否與其他對象兼容時， isInstance()方法不會引發異常。

Syntax:

句法：

    public boolean isInstance(Object o);

Parameter(s):

參數：

• It does not accept any parameter.

  它不接受任何參數。

Return value:

返回值：

The return type of this method is boolean, it returns a boolean value based on the following cases,

此方法的返回類型為boolean ，它基于以下情況返回布爾值：

• It returns true, when the given Object is instance of this Class.

  當給定的Object是此類的實例時，它返回true 。

• It returns false, when the given Object is not instance of this Class.

  當給定的Object不是該Class的實例時，它返回false 。

Example:

例：

// Java program to demonstrate the example 
// of boolean isInstance(Object o) method of Class
public class IsInstanceOfClass {
public static void main(String[] args) {
// Create and Return String class
String str = new String();
Class cl1 = str.getClass();
// Create and Return IsInstanceOfClass class
IsInstanceOfClass in = new IsInstanceOfClass();
Class cl2 = in .getClass();
// Create String and Integer class instance
String s = new String();
Integer i = new Integer(10);
// We are checking instance of which classes
boolean b1 = cl1.isInstance(s);
boolean b2 = cl2.isInstance(i);
System.out.print("Is s is an instance of" + " ");
System.out.println(cl1.getSimpleName() + ": " + b1);
System.out.print("Is i is an instance of" + " ");
System.out.println(cl2.getSimpleName() + ": " + b2);
}
}

Output

輸出量

Is s is an instance of String: true
Is i is an instance of IsInstanceOfClass: false

翻譯自: https://www.includehelp.com/java/class-class-isinstance-method-with-example.aspx

isinstance