Question

我有HashMap，其中key是bird specie，value是感知数量。这是我的代码：

public class Program {

public static void main(String[] args) {

    HashMap<String, Integer> species = new HashMap<>();
    Scanner reader = new Scanner(System.in);

    species.put("hawk (buteo jamaicensis)", 0);
    species.put("eagle (aquila chrysaetos)", 0);
    species.put("sparrow (passeridae)", 0);

    System.out.println("Add perception");
    System.out.println("What was perceived?"); //output should be "hawk"/"eagle"/"sparrow"
    String perception = reader.nextLine();

    // Change here the value of hashmap key.

    ArrayList<String> list = new ArrayList<>();
    for (HashMap.Entry<String, Integer> entry: species.entrySet()) {
        System.out.println((entry.getKey()+" : "+entry.getValue()+" perception"));
    }



}

当扫描仪询问感知内容时，我的目标是将键值从0更改为1。

例如：扫描仪正在询问＆＃34;感知到了什么？＆＃34;并且输出是＆＃34; hawk＆＃34;。那么程序应该改变关键＆＃34; hawk（buteo jamaicensis）＆＃34;从0到1的值。所以目标输出现在是：

sparrow (passeridae) : 0 perception
eagle (aquila chrysaetos) : 0 perception
hawk (buteo jamaicensis) : 1 perception

Answer 1

使用String.indexOf检查输入字符串是否为键的子字符串，如果是，则设置新值：

// Change here the value of hashmap key.
for (HashMap.Entry<String, Integer> entry: species.entrySet()) {
    if (entry.getKey().indexOf(perception) >= 0) {
        entry.setValue(entry.getValue() + 1);
}

Answer 2

for (HashMap.Entry<String, Integer> entry: species.entrySet()) {
 if (entry.getKey().equals(perception)) {
 entry.setValue(entry.getValue() + 1);
 }
}

更改HashMap键的特定值

2 个答案: