如何在数组的原始位置插入已删除的元素？

Question

在下面的代码中：

1. 首先我创建一个包含 10 个元素的数组
2. 接下来我从该数组中删除 3 个随机元素。
3. 我尝试将这 3 个随机元素添加到原始位置的原始数组中。

由于某些原因，在上面的第 3 步（在FINAL ARR控制台日志中），元素被添加到了错误的位置。 我的切片函数在步骤 3 中是否不正确？ 如果是这样，我该如何修改它才能正确？

 // Step 1. Create array of 10 elements const originalValues = maxAmount => { let finalArray = []; for (let i = 0; i < maxAmount; i++) { finalArray.push({ key1: `key1-${i+1}`, position: i }); } return finalArray; } let finalArr = originalValues(10); const finalArrOriginalLength = finalArr.length; //Step 2. Remove 3 random elements in this case key1-2, key1-7, key1-8 const removedElements = []; finalArr = finalArr.filter(elem => { if (elem.key1 === 'key1-7' || elem.key1 === 'key1-2' || elem.key1 === 'key1-8') { removedElements.push(elem); return false; } else { return true; } }); /* Step 3. Add those 3 elements back to the original positions */ removedElements.forEach(elem => { finalArr.splice(elem.position - (finalArrOriginalLength - finalArr.length) + 1, 0, elem); }); /* The inserted elements from step 3 are being inserted in the wrong position as seen when this console.log prints out finalArr */ console.log('FINAL ARR', finalArr);

Answer 1

无需从elem.position减去。

如果按原始位置对删除的元素进行排序，则应该能够将它们插入到这些位置。

这假设数组没有任何其他更改。

 // Step 1. Create array of 10 elements const originalValues = maxAmount => { let finalArray = []; for (let i = 0; i < maxAmount; i++) { finalArray.push({ key1: `key1-${i+1}`, position: i }); } return finalArray; } let finalArr = originalValues(10); const finalArrOriginalLength = finalArr.length; //Step 2. Remove 3 random elements in this case key1-2, key1-7, key1-8 const removedElements = []; finalArr = finalArr.filter(elem => { if (elem.key1 === 'key1-7' || elem.key1 === 'key1-2' || elem.key1 === 'key1-8') { removedElements.push(elem); return false; } else { return true; } }); /* Step 3. Add those 3 elements back to the original positions */ removedElements.sort((a, b) => a.position - b.position).forEach(elem => { finalArr.splice(elem.position, 0, elem); }); console.log('FINAL ARR', finalArr);

Answer 2

尝试这个...

 // Step 1. Create array of 10 elements const originalValues = maxAmount => { let finalArray = []; for (let i = 0; i < maxAmount; i++) { finalArray.push({ key1: `key1-${i+1}`, position: i }); } return finalArray; } let finalArr = originalValues(10); const finalArrOriginalLength = finalArr.length; //Step 2. Remove 3 random elements in this case key1-2, key1-7, key1-8 const removedElements = []; finalArr = finalArr.filter(elem => { if (elem.key1 === 'key1-7' || elem.key1 === 'key1-2' || elem.key1 === 'key1-8') { removedElements.push(elem); return false; } else { return true; } }); // Step 3. Add those 3 elements back to the original positions removedElements .sort((a,b)=>{return a.position > b.position ? 0 : 1 }); removedElements.forEach(elem => { finalArr.splice(elem.position, 0, elem); }); /* The inserted elements from step 3 are being inserted in the wrong position as seen when this console.log prints out finalArr */ console.log('FINAL ARR', finalArr);