Understanding this removeAll java method with arrayList

Question

This method\'s duty is to remove all occurrences of the value toRemove from the arrayList. The remaining elements should just be shifted toward the beginning of

Answer 1

Why do we start the second for-loop one after where the last one was?

Each time an occurence is found, we want to left shift by 1 all following values of the arraylist.

Why within that second for loop do we use list.set(), I understand that set method takes in two arguments, the index position, and the element to sub into that designated position. Why j - 1?

j-1 is used to shift left by 1 .

Why after this second loop is over is there the line: list.set(list. sise () - 1, 0) ?

We shifted values left, but the value at the last index (size-1) has not been replaced by anything, we want it to be 0 .

why the i--?

As the value at the current index has been overwritten by another value, we want to start next iteration at the same index (i-- compensating i++).