如何過濾此數組中大於或等於90的標記？

Question

let students = [
  {"Name": "Priya","marks": [50, 60, 70, 80, 90]},
  {"Name": "Ankita","marks": [80, 90, 95]}
] 

結果應該是這樣，

[{"Name": "Priya", "marks": [90]}, {"Name": "Ankita","marks": [90,95]}]

Answer 1

Nikhil的第一個答案將修改原始數組，不建議這樣做，因此您可以簡單地執行此操作。

let students = [
      {"Name": "Priya","marks": [50, 60, 70, 80, 90]},
      {"Name": "Ankita","marks": [80, 90, 95]}
    ]

現在，我要過濾大於或等於90的標記，代碼將如下所示。

students.map((student) => {
  return {...student, 
          marks: student.marks.filter((mark) => mark >= 90)
         }
}) 
// Result will be [{"Name": "Priya", "marks": [90]}, {"Name": "Ankita","marks": [90,95]}]

Spread operator將擴展student ，然后將其marks key替換為已filtered marks value 。

如果您不使用傳播運算符，

students.map((student) => student.marks.filter((mark) => mark >= 90))
// Result will be [[90],[90]]

然后，您將僅獲得過濾后的值，而不是尚未應用過濾器的值。

Answer 2

使用Array.filter可以根據條件過濾數組的值。

更新現有數組 （使用Array.forEach ）

 let students = [{"Name": "Priya","marks": [50, 60, 70, 80, 90]},{"Name": "Ankita","marks": [80, 90, 95]}]; students.forEach(o => o.marks = o.marks.filter(v => v >= 90)); console.log(students); 

創建新數組 （使用Array.map和Object.assign ）

 let students = [{"Name": "Priya","marks": [50, 60, 70, 80, 90]},{"Name": "Ankita","marks": [80, 90, 95]}]; let result = students.map(o => Object.assign({}, o, {marks : o.marks.filter(v => v >= 90)})); console.log(result); 

Answer 3

您可以使用.map() .filter()和Object.assign()方法：

 let data = [ {"Name": "Priya","marks": [50, 60, 70, 80, 90]}, {"Name": "Ankita","marks": [80, 90, 95]} ]; let result = data.map( o => Object.assign(o, {marks: o.marks.filter(v => v >= 90)}) ); console.log(result); 

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