Array[i++] vs Array [++i] in a for loop in java

Question

Please someone tell me about the difference between Array[i++] vs Array[++i] in a loop.

• int arr[5]={1,3,5,6,8}; int a=0,b=0; for(int i=0;i<5;i++){
  a=arr[++i]; b=arr[i++]; }