Remove object from array of objects in Javascript

splice-object-array.js

//Data that contains information of some I already have copies of
let allFiles = [ 
  { filecode: '48099',
    filedate: '20180430',
    amountinfile: '55' },
  { filecode: '48074',
    filedate: '20180429',
    amountinfile: '2'},
  { filecode: '48075',
    filedate: '20180429',
    amountinfile: '97' },
  { filecode: '48051',
    filedate: '20180428',
    amountinfile: '101' },
  { filecode: '48027',
    filedate: '20180427',
    amountinfile: '48' },
  { filecode: '48003',
    filedate: '20180426',
    amountinfile: '143' },
  { filecode: '47978',
    filedate: '20180425',
    amountinfile: '1' },
  { filecode: '47979',
    filedate: '20180425',
    amountinfile: '80' },
  { filecode: '47954',
    filedate: '20180424',
    amountinfile: '1' },
  { filecode: '47955',
    filedate: '20180424',
    amountinfile: '79' },
  { filecode: '47924',
    filedate: '20180423',
    amountinfile: '1' },
  { filecode: '47925',
    filedate: '20180423',
    amountinfile: '90' },
  { filecode: '47900',
    filedate: '20180422',
    amountinfile: '6' },
  { filecode: '47901',
    filedate: '20180422',
    amountinfile: '117' },
  { filecode: '47876',
    filedate: '20180421',
    amountinfile: '2' },
  { filecode: '47877',
    filedate: '20180421',
    amountinfile: '130' },
  { filecode: '47850',
    filedate: '20180420',
    amountinfile: '1' },
  { filecode: '47851',
    filedate: '20180420',
    amountinfile: '159' },
  { filecode: '47829',
    filedate: '20180419',
    amountinfile: '1' },
  { filecode: '47830',
    filedate: '20180419',
    amountinfile: '125' },
  { filecode: '47805',
    filedate: '20180418',
    amountinfile: '1' },
  { filecode: '47806',
    filedate: '20180418',
    amountinfile: '74' },
  { filecode: '47782',
    filedate: '20180417',
    amountinfile: '81' },
  { filecode: '47752',
    filedate: '20180416',
    amountinfile: '54' },
  { filecode: '47728',
    filedate: '20180415',
    amountinfile: '150' }
    ];

//Array of files I already have
let alreadyHaveFiles = [
       '48099','48074','48075','48051','48027','48003','47978','47979','47954','47955',
       '47924','47925','47900', '47901', '47876','47877', '47850'
];

//See how many files I already have
console.log(`Number of files I already have: ${alreadyHaveFiles.length}`)

//Create an independent copy of the allFiles
let tempFiles = allFiles.slice(0);

//Check length of allfiles and tempFiles before
console.log(`Before:\n Files: ${allFiles.length} TempFiles: ${tempFiles.length}`);

//Remove files that I already have from tempFiles and leave allFiles untouched
allFiles.forEach((element) => {
  if(alreadyHaveFiles.includes(element['filecode'])){
    let removeIndex = tempFiles.map((item) => item['filecode']).indexOf(element['filecode']);
    tempFiles.splice(removeIndex, 1);
  }
});

//Check length of allFiles and tempFiles after
console.log(`After:\n Files: ${allFiles.length} TempFiles: ${tempFiles.length}`)

//console.log shows the following

// Number of files I already have: 17
// Before:
// Files: 25 TempFiles: 25
// After:
// Files: 25 TempFiles: 8