TS - 如何從舊陣列和新陣列中獲取陣列中已刪除和添加的項目？

Question

認爲我們有這個

oldArray = [ 
    { id: 1, position: 'DEV OM'}, 
    { id: 2, position: 'Senior Developer'}, 
] 

newArray = [ 
    { id: 2, position: 'Senior Developer'}, 
    { id: 3, position: 'Junior Developer'}, 
] 

現在，我們怎樣才能在這些陣列的刪除，並添加項目嗎？

addedItems = getAddedItems(oldArray, newArray) 
removedItems = getRemovedItems(oldArray, newArray) 


// Output for addedItems 
[ 
    { id: 3, position: 'Junior Developer'} 
] 

// Output for removedItems 
[ 
    { id: 1, position: 'DEV OM'} 
] 

進出口使用打字稿/ angular2應用

Answer 1

你需要的是找到2個陣列之間的差異的函數：

let oldArray = [ 
 
    { id: 1, position: 'DEV OM'}, 
 
    { id: 2, position: 'Senior Developer'} 
 
] 
 

 
let newArray = [ 
 
    { id: 2, position: 'Senior Developer'}, 
 
    { id: 3, position: 'Junior Developer'} 
 
] 
 

 
function difference(a,b) { 
 
    return a.filter(itema => !b.some(itemb => itemb.id===itema.id)); 
 
} 
 

 
console.log(difference(oldArray,newArray)) 
 
console.log(difference(newArray,oldArray))