如何访问 json 数据的值 0 (react-native) expo

Question

我有一些 json 数据，例如：

[{"timestamp":"2020-03-23T14:00:00.000Z","symbol":"AAL","name":"American Airlines Group","industry":"Industrials","open":10.9,"high":11.36,"low":10.01,"close":10.25,"volumes":55494100},

{"timestamp":"2020-03-22T14:00:00.000Z","symbol":"AAL","name":"American Airlines Group","industry":"Industrials","open":10.6526,"high":12,"low":10.3,"close":10.38,"volumes":62681800},


{"timestamp":"2020-03-19T14:00:00.000Z","symbol":"AAL","name":"American Airlines Group","industry":"Industrials","open":11.6,"high":12.16,"low":10.01,"close":10.29,"volumes":71584500},{"timestamp":"2020-03-18T14:00:00.000Z","symbol":"AAL","name":"American Airlines 

我只想获取 0 索引值：

This one:   [{"timestamp":"2020-03-23T14:00:00.000Z","symbol":"AAL","name":"American Airlines Group","industry":"Industrials","open":10.9,"high":11.36,"low":10.01,"close":10.25,"volumes":55494100},{"timestamp":"2020-03-22T14:00:00.000Z",

我的代码：

  let movies = state.myListData.map((val) => {
    return (
      <View key={val.symbol} style={styles.text}>
        <Text style={styles.text} key={val.symbol}>
          {val.high}
        </Text>
        <Text style={styles.text} key={val.symbol}>
          {val.close}
        </Text>
      </View>
    );
  });

现在我得到了所有的值，但我怎样才能只得到值 0？ 有没有办法做到这一点？

Answer 1

你可以简单地这样做：

 let item = state.myListData[0]; let movie = ( <View key={item.symbol} style={styles.text}> <Text style={styles.text} key={item.symbol}> {item.high} </Text> <Text style={styles.text} key={item.symbol}> {item.close} </Text> </View> )