jsonObject.has()是干嘛的?

Question

jsonObject.has()是干嘛的?

  String jsonStr=new String(data);

        try {

            JSONObject jsonObject=new JSONObject(jsonStr);

            if (jsonObject.has("fileUri")){

            }

        } catch (JSONException e) {

            e.printStackTrace();

        }

Answer 1

Determine if the JSONObject contains a specific key.Parameters:key A key string.Returns:true if the key exists in the JSONObject.&nbsp; &nbsp; public boolean has(String key) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;return this.map.containsKey(key);&nbsp; &nbsp; }&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; public JSONObject() {&nbsp; &nbsp; &nbsp; &nbsp; this.map = new HashMap<String, Object>();&nbsp; &nbsp; }可以看出是通过使用Map.containsKey(key)方法来做出判断的。

Answer 2

Answer 3

判断类中是否有某个字段

Answer 4

查询对象是否包含该key,返回boolean，与Map.containsKey(key)用法一致