Snippets-Bubblesort need to adjust boundaries.

[Suiyueemperor]

 public static void bubbleSort(int[] arr) {
    var lastIndex = arr.length - 1;
    for(var j = 0; j < lastIndex; j++) {
      for(var i = 0; i < lastIndex - j; i++) {
        if(arr[i] > arr[i + 1]) {
          var tmp = arr[i];
          arr[i] = arr[i + 1];
          arr[i + 1] = tmp;
        }
      }
    }
  }

The outermost loop can be run at most n-1 times, so the changes are as follows

for(var j = 0; j < lastIndex - 1; j++) {
      for(var i = 0; i < lastIndex - j - 1; i++) {