Looping over objects in array and adding property to each

Question

I'm getting an array of files, and then I want to add the date and size properties to each of those file objects, but using the code below, they don't get added. I know that's my fs.statSync(p + file).mtime.getTime() and fs.statSync(p + file).size have values in them.

var files = fs.readdirSync(p);

files.sort(function(a, b) {
           return fs.statSync(p + a).mtime.getTime() - 
                  fs.statSync(p + b).mtime.getTime();
});

files.forEach(function(file) {
    file.date = fs.statSync(p + file).mtime.getTime();
    file.size = fs.statSync(p + file).size;
});

console.log('files::'+files); // doesn' have the new file.date and file.size property.

no its just not adding the new properties. The array stays in the same form as when it started. — Kiksy
– Kiksy, Commented Jul 31, 2014 at 15:23
What if you log in the foreach-callback? Have you tried file['date']? — Hank Lapidez
– Hank Lapidez, Commented Jul 31, 2014 at 15:23

Eugene Obrezkov · Accepted Answer · 2014-07-31 15:24:28Z

3

When you writing value into file variable it's not saving because file it's variable that lives into local scope. So a quick solution for this:

var files = fs.readdirSync(p),
    result = [];

files.sort(function(a, b) {
           return fs.statSync(p + a).mtime.getTime() - 
                  fs.statSync(p + b).mtime.getTime();
});

files.forEach(function(file) {
    file.date = fs.statSync(p + file).mtime.getTime();
    file.size = fs.statSync(p + file).size;
    result.push(file);
});

console.log('files::' + result);

answered Jul 31, 2014 at 15:24

Eugene Obrezkov

2,9962 gold badges19 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Andy · Accepted Answer · 2014-07-31 15:28:16Z

0

Similar to Eugene's answer, but this uses map:

files = files.map(function(file) {
  file.date = fs.statSync(p + file).mtime.getTime();
  file.size = fs.statSync(p + file).size;
  return file;
});

DEMO

answered Jul 31, 2014 at 15:28

Andy

63.6k13 gold badges72 silver badges99 bronze badges

Comments

mike · Accepted Answer · 2014-07-31 15:28:10Z

0

The file variable is a local variable. Without having to create a new array as Eugene did, you can update the original array in this way:

var files = fs.readdirSync(p);

files.sort(function(a, b) {
           return fs.statSync(p + a).mtime.getTime() - 
                  fs.statSync(p + b).mtime.getTime();
});

files.forEach(function(file, index, array) {
    array[index].date = fs.statSync(p + file).mtime.getTime();
    array[index].size = fs.statSync(p + file).size;
});

console.log('files::'+files);

answered Jul 31, 2014 at 15:28

mike

5,2312 gold badges29 silver badges32 bronze badges

Collectives™ on Stack Overflow

Looping over objects in array and adding property to each

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related