Java Collections frequency() Method

The frequency() method of Java Collections class is used to get the number of elements in the specified collection equal to the specified object.

Syntax

Following is the declaration of frequency() method:

Parameter

Returns

The frequency() method returns the number of elements in the collections c equal to the specified object obj.

Exceptions

NullPointerException- This exception will be thrown if collection c is null.

Compatibility Version

Java 1.5 and above

Example 1

Output:

List of elements: [Java, COBOL, Java, C++, Java]
Frequency of the Word: 3

Example 2

Output:

List of elements: [1, 2, 1, 3, 2, 3, 4]
Count all with frequency:
1: 2
2: 2
3: 2
4: 1

Example 3

Output:

Frequency of 20 is: 4