(javascript) JSON.parse() 更改 json 的内容

Question

I'm making a practice tool for a game that helps you to learn how to play songs with the piano and what i'm trying to is get all the notes that are pressed within 50ms from one another and make them display as "you have to press them together" now, this seems to be working but when i pass the string of the song to the parser, it changes the content of the array. i've used the exact same method to parse the object in other functions and it works as expected, here not, this is (part) of the unparsed array

[{"time":2937,"key":"Key2"},
{"time":2943,"key":"Key7"},
{"time":2949,"key":"Key0"},
{"time":4297,"key":"Key6"},
{"time":4306,"key":"Key11"},
{"time":4315,"key":"Key2"},
{"time":5547,"key":"Key5"},
{"time":5549,"key":"Key2"},
{"time":5554,"key":"Key7"},
{"time":7480,"key":"Key8"},
{"time":7814,"key":"Key9"},

this is after being parsed

0: {time: 2943, key: "Key7"}
1: {time: 4297, key: "Key6"}
2: {time: 4306, key: "Key11"}
3: {time: 4315, key: "Key2"}
4: {time: 5547, key: "Key5"}
5: {time: 5549, key: "Key2"}
6: {time: 5554, key: "Key7"}
7: {time: 7480, key: "Key8"}
8: {time: 7814, key: "Key9"}
9: {time: 8158, key: "Key5"}
10: {time: 8166, key: "Key10"}

why does this happen and how can i fix it? the code is litterally:

console.log(song)
trainingSong = JSON.parse(song)
console.log(trainingSong)

Answer 1

Use JSON.stringify to stringify the code & then use JSON.parse to parse it.

 console.log( JSON.stringify([ { time: 2937, key: "Key2" }, { time: 2943, key: "Key7" }, { time: 2949, key: "Key0" }, { time: 4297, key: "Key6" }, { time: 4306, key: "Key11" }, { time: 4315, key: "Key2" }, { time: 5547, key: "Key5" }, { time: 5549, key: "Key2" }, { time: 5554, key: "Key7" }, { time: 7480, key: "Key8" }, { time: 7814, key: "Key9" }, ]) );