JavaScript 获取对象最后一个键值对 - 轻松提取数据
可以使用 Object.keys() 方法获取对象的键数组，然后取最后一个即可：
const data = {
"2023-02-22": {
"1046": {
"Num": 1,
"Maxnumber": '64'
},
"3014": {
"Num": 7,
"Maxnumber": 47
},
"10021": {
"Num": 4,
"Maxnumber": 32
},
"10023": {
"Num": 1,
"Maxnumber": '105'
}
},
"2023-02-23": {
"1006": {
"Num": 1,
"Maxnumber": '32'
},
"1046": {
"Num": 1,
"Maxnumber": '64'
},
"3011": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 2,
"Maxnumber": 32
},
"3014": {
"Num": 91,
"Maxnumber": 62
},
"3017": {
"Num": 2,
"Maxnumber": 47
},
"5260": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 16,
"Maxnumber": 112
},
"10023": {
"Num": 1,
"Maxnumber": '32'
},
"10049": {
"Num": 1,
"Maxnumber": '112'
},
"10101": {
"Num": 6,
"Maxnumber": 32
}
},
"2023-02-24": {
"1006": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 4,
"Maxnumber": 32
},
"3014": {
"Num": 87,
"Maxnumber": 61
},
"5013": {
"Num": 1,
"Maxnumber": '32'
},
"10000": {
"Num": 1,
"Maxnumber": '64'
},
"10021": {
"Num": 13,
"Maxnumber": 79
},
"10101": {
"Num": 4,
"Maxnumber": 48
}
},
"2023-02-25": {
"3014": {
"Num": 3,
"Maxnumber": 32
},
"5260": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 9,
"Maxnumber": 128
},
"10049": {
"Num": 1,
"Maxnumber": '64'
},
"10101": {
"Num": 1,
"Maxnumber": '32'
}
},
"2023-02-26": {
"3013": {
"Num": 2,
"Maxnumber": 32
},
"3014": {
"Num": 13,
"Maxnumber": 32
},
"3017": {
"Num": 2,
"Maxnumber": 32
},
"10021": {
"Num": 9,
"Maxnumber": 48
},
"10101": {
"Num": 4,
"Maxnumber": 47
}
},
"2023-02-27": {
"3014": {
"Num": 7,
"Maxnumber": 46
},
"10021": {
"Num": 5,
"Maxnumber": 75
},
"10039": {
"Num": 1,
"Maxnumber": '48'
},
"10101": {
"Num": 6,
"Maxnumber": 45
}
},
"2023-02-28": {
"1011": {
"Num": 1,
"Maxnumber": '32'
},
"3014": {
"Num": 19,
"Maxnumber": 47
},
"3199": {
"Num": 1,
"Maxnumber": '32'
},
"5013": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 11,
"Maxnumber": 96
},
"10049": {
"Num": 1,
"Maxnumber": '32'
},
"10101": {
"Num": 1,
"Maxnumber": '45'
}
},
"2023-03-01": {
"1006": {
"Num": 1,
"Maxnumber": '32'
},
"1154": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 2,
"Maxnumber": 32
},
"3014": {
"Num": 32,
"Maxnumber": 48
},
"3017": {
"Num": 1,
"Maxnumber": '32'
},
"3199": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 13,
"Maxnumber": 64
},
"10049": {
"Num": 1,
"Maxnumber": '32'
},
"10101": {
"Num": 8,
"Maxnumber": 48
}
},
"2023-03-02": {
"3011": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 2,
"Maxnumber": 32
},
"3014": {
"Num": 47,
"Maxnumber": 62
},
"10021": {
"Num": 12,
"Maxnumber": 112
},
"10101": {
"Num": 7,
"Maxnumber": 60
}
},
"2023-03-03": {
"1046": {
"Num": 1,
"Maxnumber": '60'
},
"3011": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 6,
"Maxnumber": 32
},
"3014": {
"Num": 66,
"Maxnumber": 48
},
"3017": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 24,
"Maxnumber": 75
},
"10101": {
"Num": 7,
"Maxnumber": 45
}
},
"2023-03-04": {
"3011": {
"Num": 1,
"Maxnumber": '32'
},
"3013": {
"Num": 3,
"Maxnumber": 32
},
"3014": {
"Num": 49,
"Maxnumber": 48
},
"5260": {
"Num": 1,
"Maxnumber": '32'
},
"10021": {
"Num": 13,
"Maxnumber": 48
},
"10049": {
"Num": 1,
"Maxnumber": '32'
},
"10101": {
"Num": 6,
"Maxnumber": 32
}
}
};
const lastDate = Object.keys(data)[Object.keys(data).length - 1];
console.log(lastDate); // '2023-03-04'
其他方法：
- 使用
Object.entries()方法获取键值对数组，然后取最后一个即可：
const lastEntry = Object.entries(data)[Object.entries(data).length - 1];
console.log(lastEntry[0]); // '2023-03-04'
- 使用
for...in循环遍历对象，记录最后一个键即可：
let lastKey = null;
for (const key in data) {
lastKey = key;
}
console.log(lastKey); // '2023-03-04'
选择最适合你的方法，根据实际情况进行应用。
原文地址: https://www.cveoy.top/t/topic/m1D2 著作权归作者所有。请勿转载和采集!