数组相关

Arrays.sort(）

index=Arrays.binarySearch(array,2)

分段数组复制

System.arraycopy(original, 0, destination, 0, index);

数组反转

Collections.reverse(arrayList);

数组最大值，最小值

int min = (int) Collections.min(Arrays.asList(numbers));

int max = (int) Collections.max(Arrays.asList(numbers));

 

arraytoList：List list = new ArrayList(Arrays.asList(a));

 list.addAll(Arrays.asList(b));

数组合并

Object[] c = list.toArray();

数组填充

Arrays.fill(array, 100);

Arrays.fill(array, 3, 6, 50);

起点结束点，结束点不包括

数组扩容：

System.arraycopy(names, 0, extended, 0, names.length);

前面粘贴到后面

ArrayList.remove()

ArrayList.removeAll() 求差

objArray2.add(0,"common1");
        objArray2.add(1,"common2");
        objArray2.add(2,"notcommon");
        objArray2.add(3,"notcommon1");
        objArray.add(0,"common1");
        objArray.add(1,"common2");
        objArray.add(2,"notcommon2");
        System.out.println("array1 的元素" +objArray);
        System.out.println("array2 的元素" +objArray2);
        objArray.removeAll(objArray2);

 ArrayList.retainAll () 求交集

ArrayList.contains()

Arrays.equals(a,b)