手动实现HashMap3_实现toString方法，方便查看Map中的键值对信息

手动实现HashMap3_实现toString方法，方便查看Map中的键值对信息

toString方法代码块

public String toString() {
		StringBuilder sb = new StringBuilder('[');
		for(int i=0;i<table.length;i++) {
			Node2 temp = table[i];
			while(temp!=null) {
				sb.append(temp.key+":"+temp.value+",");
				temp = temp.next;
			}
		}
		sb.setCharAt(sb.length()-1, ']');
		return sb.toString();
	}

实现代码块

public class SxtHashMap3 {
	Node2[] table;//位桶数组 bucket array
	int size;//存放键对个数
	public SxtHashMap3() {
		table = new Node2[16];//长度一般为2的整数次幂
	}
	public void put(Object key,Object value) {
		boolean repeat = false;
		Node2 newNode = new Node2();
		newNode.hash = myHash(key.hashCode(),table.length);
		newNode.key = key;
		newNode.value = value;
		Node2 temp = table[newNode.hash];
		Node2 LinkedLast = null;//存储最后一个节点
		//当前节点为空则直接放入
		if(temp==null) {
			repeat = true;
			table[newNode.hash] = newNode;
		}else {
			while(temp!=null) {
				//判断key是否重复，若重复则覆盖（只覆盖value值，next,key,hash值不变）
				if(temp.key.equals(key)) {
					temp.value = value;
				}else {
				//若不重复则遍历
				LinkedLast = temp;
				temp = temp.next;
				}
			}
		}
		if(!repeat) {
			LinkedLast.next = newNode;
		}
	}
	public static int myHash(int v,int length) {
		return v&(length-1);
	}
	public static void main(String[] args) {
		SxtHashMap3 map2 = new SxtHashMap3();
		//找出50内hash值相同的key值
		for(int i=0;i<50;i++) {
			System.out.println(i+"---"+myHash(i, 16));
		}//17,33,49hash值相同
		map2.put(17, "阿狸");
		map2.put(33, "阿卡丽");
		map2.put(49, "瑞雯");
		System.out.println(map2);
	}
	public String toString() {
		StringBuilder sb = new StringBuilder('[');
		for(int i=0;i<table.length;i++) {
			Node2 temp = table[i];
			while(temp!=null) {
				sb.append(temp.key+":"+temp.value+",");
				temp = temp.next;
			}
		}
		sb.setCharAt(sb.length()-1, ']');
		return sb.toString();
	}	
}

效果