/*
自定义实现一个ArrayList,体会底层原理
@author 晚风花间寺中人
*/
public class ArrayList02 {
private Object[] elementDate;//核心数组
private int size; //数组长度
private static final int DEFALT_CAPACITY=10;
public ArrayList02(){
elementDate = new Object[DEFALT_CAPACITY];
}
public ArrayList02(int capacity ){
elementDate = new Object[capacity];
}
public void add(Object obj){
elementDate[size++]=obj;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("[");
for (int i =0;i<size;i++){
sb.append(elementDate[i]+",");
}
sb.setCharAt(sb.length()-1,']');
return sb.toString();
}
public static void main(String[] args) {
ArrayList02 s = new ArrayList02(20);
s.add("aa");
s.add("bb");
System.out.println(s);
}
}
运行结果:
[aa,bb]
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