JavaScript 中如何检查两个对象的匹配数据是否很少

Question

I have data like this:

Array = [
  { 0: { Id: 18, Time: 3 } },
  { 1: { Id: 5, Time: 7 } },
  { 2: { Id: 18, Time: 10 } },
  { 3: { Id: 2, Time: 9 } },
];

As you can see Object 0 & Object 2 has same Id. I want to perform an operation which will check whether any of the Objects has same Id in it and return true or false.

Answer 1

The below code might help.

 function getMatch(array) { var idArray = array.map(a => a.Id); return idArray.some((a, index) => idArray.indexOf(a) !== index); } var arr = [ { Id: 18, Time: 3 }, { Id: 5, Time: 7 }, { Id: 18, Time: 10 }, { Id: 2, Time: 9 } ]; console.log(getMatch(arr));

Answer 2

You can map your array of objects its entries, and then map the entires to its Id to get an array of Ids. You can put this array of ids into a set to remove duplicates and compare it with the length of the array to check if an Id was removed when creating the set.

 const arr = [{ 0: { Id: 18, Time: 3 } }, { 1: { Id: 5, Time: 7 } }, { 2: { Id: 18, Time: 10 } }, { 3: { Id: 2, Time: 9 } }]; const ids = arr.map(Object.values).map(([{Id}]) => Id); const hasSameId = ids.length !== new Set(ids).size; console.log(hasSameId);

Answer 3

Use this function which will tell same id exist in your array.

 SameIdMatch() { let idList = []; for (let i = 0; i < Array.length; i++) { if(idList.indexOf(Array[i].Id) === -1) { idList.push(Array[i].Id); return true; } else { return false; } } }

Answer 4

Try this one liner.

 const input = [ { 0: { Id: 18, Time: 3 } }, { 1: { Id: 5, Time: 7 } }, { 2: { Id: 18, Time: 10 } }, { 3: { Id: 2, Time: 9 } } ]; const hasDuplicate = input.length !== [...new Set(input.map((item, index) => item[index].Id))].length; console.log(hasDuplicate);