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Replace all occurrences of specified element of Java ArrayList Example

  1. /*
  2.   Replace all occurrences of specified element of Java ArrayList Example
  3.   This java example shows how to replace all occurrences of a specified element
  4.   of Java ArrayList using replaceAll method of Collections class.
  5. */
  6.  
  7. import java.util.ArrayList;
  8. import java.util.Collections;
  9.  
  10. public class ReplaceAllArrayListExample {
  11.  
  12.   public static void main(String[] args) {
  13.    
  14.     //create an ArrayList object
  15.     ArrayList arrayList = new ArrayList();
  16.    
  17.     //Add elements to Arraylist
  18.     arrayList.add("A");
  19.     arrayList.add("B");
  20.     arrayList.add("A");
  21.     arrayList.add("C");
  22.     arrayList.add("D");
  23.  
  24.     System.out.println("ArrayList Contains : " + arrayList);
  25.    
  26.     /*
  27.       To replace all occurrences of specified element of Java ArrayList use,
  28.       static boolean replaceAll(List list, Object oldVal, Object newVal) method
  29.       of Collections class.
  30.      
  31.       This method returns true if the list contained one more elements replaced.
  32.      
  33.     */
  34.    
  35.     Collections.replaceAll(arrayList, "A","Replace All");
  36.    
  37.     System.out.println("After Replace All, ArrayList Contains : " + arrayList);
  38.   }
  39. }
  40.  
  41. /*
  42. Output would be
  43. ArrayList Contains : [A, B, A, C, D]
  44. After Replace All, ArrayList Contains : [Replace All, B, Replace All, C, D]
  45. */