java:手写MyArrayLisy的常用方法,增删改查
package arrays.myArray;
public class MyArrayList {
private Object[] arrObj = new Object[3];
private int size = 0;
// 长度
public int size() {
return size;
}
// insert
public void add(Object obj) {
add(size,obj);
}
// update
// 把前面的往后移动
public void add(int index, Object obj) {
if(size==arrObj.length){
Object[] temp=new Object[size*2];
for(int i=0;i<arrObj.length;i++){
temp[i]=arrObj[i];
}
arrObj=temp;
}
//从前往后
for (int i =size; i>index ; i--) {
arrObj[i] = arrObj[i-1];
}
arrObj[index]=obj;
size++;
}
// delete
// 把后面的往前移动
public void remove(int index) {
size--;
for (int i =index;i<size; i++) {
arrObj[i] = arrObj[i+1];
}
}
public Object get(int index) {
return arrObj[index];
}
}