EN
Java - instanceof keyword simple usage example
4 points
In java with instanceof keyword we can check if our object is instance of specific class or interface.
Quick solution:
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List<String> results = new ArrayList<>();2
3
if (results instanceof List) {4
// results is instance of List5
}Example with ArrayList instead of List:
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ArrayList<String> results = new ArrayList<>();2
3
if (results instanceof List) {4
// results is instance of List5
}Example with Object instead of List
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Object results = new ArrayList<>();2
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if (results instanceof List) {4
// results is also instance of List5
}xxxxxxxxxx1
import java.util.ArrayList;2
import java.util.List;3
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public class Example {5
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public static void main(String[] args) {7
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List<String> results = new ArrayList<>();9
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if (results instanceof List) {11
System.out.println("Yes, results is instance of List");12
} else {13
System.out.println("No, results is NOT instance of List");14
}15
}16
}Output:
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Yes, results is instance of Listxxxxxxxxxx1
import java.util.ArrayList;2
import java.util.List;3
4
public class Example {5
6
public static void main(String[] args) {7
8
Object results = new ArrayList<>();9
10
if (results instanceof List) {11
System.out.println("Yes, results is instance of List");12
} else {13
System.out.println("No, results is NOT instance of List");14
}15
16
if (results instanceof String) {17
System.out.println("Yes, results is instance of String");18
} else {19
System.out.println("No, results is NOT instance of String");20
}21
}22
}Output:
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Yes, results is instance of List2
No, results is NOT instance of String
