How to replace all occurrences of a given object in the list?

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The java.util.Collections class consists exclusively of static methods that operate on or return collections. It contains polymorphic algorithms that operate on collections, “wrappers”, which return a new collection backed by a specified collection, and a few other odds and ends.

Collections.replaceAll() method will replaces all occurrences of one specified value in a list with another.
Syntax: public static boolean replaceAll(List list,T oldVal,T newVal)

Example

package com.w3schools;
 
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
 
public class Test { 
    public static void main(String a[]){         
        List<String> list = new ArrayList<String>();
        list.add("vikas");
        list.add("amit");
        list.add("ajay");
        list.add("mahesh");
        list.add("anil");
        System.out.println(list);
        //replace anil with jack
        Collections.replaceAll(list, "anil", "jack");
        System.out.println(list);
    }
}

Output

[vikas, amit, ajay, mahesh, anil]
[vikas, amit, ajay, mahesh, jack]

Java Collections class examples