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Replace an element at specified index of Java ArrayList Example

  1. /*
  2.   Replace an element at specified index of Java ArrayList Example
  3.   This Java Example shows how to replace an element at specified index of java
  4.   ArrayList object using set method.
  5. */
  6.  
  7. import java.util.ArrayList;
  8.  
  9. public class ReplaceElementAtSpecifiedIndexArrayListExample {
  10.  
  11.   public static void main(String[] args) {
  12.     //create an ArrayList object
  13.     ArrayList arrayList = new ArrayList();
  14.    
  15.     //Add elements to Arraylist
  16.     arrayList.add("1");
  17.     arrayList.add("2");
  18.     arrayList.add("3");
  19.    
  20.     /*
  21.       To replace an element at the specified index of ArrayList use
  22.       Object set(int index, Object obj) method.
  23.       This method replaces the specified element at the specified index in the
  24.       ArrayList and returns the element previously at the specified position.
  25.     */
  26.     arrayList.set(1,"REPLACED ELEMENT");
  27.  
  28.     System.out.println("ArrayList contains...");
  29.     //display elements of ArrayList
  30.     for(int index=0; index < arrayList.size(); index++)
  31.       System.out.println(arrayList.get(index));
  32.    
  33.   }
  34. }
  35.  
  36. /*
  37. Output would be
  38. ArrayList contains...
  39. 1
  40. REPLACED ELEMENT
  41. 3
  42. */