Java underlying implementation container, java underlying container

Java underlying implementation container, java underlying container

1 package StudyCollection; 2 3/** 4 * underlying implementation of simple containers 5*6 * @ author ouyang-an Thank you, Mr. Gao Qi from Shang xuexiang, 7 */8 9 public class MakeArray {10 private Object [] elementData; 11 private int size; 12 13 // No parameter constructor 14 public MakeArray () {15 this (10 ); // The default size is 1016} 17 18. // 19 public MakeArray (int initialCapacity) {20 if (initialCapacity <0) {21 try {22 throw new Exception ("the array is out of bounds! "); 23} catch (Exception e) {24 e. printStackTrace (); 25} 26} 27 elementData = new Object [initialCapacity]; 28} 29 30 // add () method 31 public void add (Object obj) {32 if (size = elementData. length) {33 Object [] newArray = new Object [size * 2]; 34 System. arraycopy (elementData, 0, newArray, 0,35 elementData. length); 36 elementData = newArray; 37} 38 elementData [size] = obj; 39 size ++; 40} 41 42 // size Method 43 public int size () {44 return size; 45} 46 47 // determines whether the array is null. 48 public boolean isEmpty () {49 return size = 0; 50} 51 52 // traverse 53 public void iteratesMethod () {54 for (int I = 0; I <size; I ++) {55 Object array_element = elementData [I]; 56 System. out. println (I + ":" + array_element); 57} 58} 59 60 // get Method 61 public Object get (int index) {62 if (index> = size) {63 try {64 throw new Exception (); 65} catch (Exception e) {66 e. printStackTrace (); 67} 68} 69 return elementData [index]; 70} 71 72 // set method 73 public Object set (int index, Object nObject) {74 return elementData [index] = nObject; 75} 76 77 public static void main (String [] args) {78 MakeArray list = new MakeArray (); 79 list. add ("11"); 80 list. add ("22"); 81 list. add ("33"); 82 list. add ("44"); 83 list. iteratesMethod (); 84 System. out. println ("------------------------"); 85 System. out. println (list. size); 86 System. out. println ("------------------------"); 87 System. out. println (list. isEmpty (); 88 System. out. println ("------------------------"); 89 System. out. println (list. get (3); 90 System. out. println ("------------------------"); 91 System. out. println (list. set (2, "ouyangan"); 92 System. out. println ("------------------------"); 93 list. iteratesMethod (); 94} 95}