Javascriptを/私はこのような構造で働いている

Question

空の配列を削除する方法をlodash：

[ 
    [ 
     { 
     "comments":"asd", 
     "movement":"Back Squat", 
     "userID":"wDHZv3OL55SIymHkhMUejNleNkx1", 
     "weight":"330" 
     } 
    ], 
    [ 
     { 
     "comments":"asd", 
     "movement":"Bench Press", 
     "userID":"wDHZv3OL55SIymHkhMUejNleNkx1", 
     "weight":"100" 
     } 
    ], 
    [ 
     { 
     "comments":"Comment", 
     "movement":"Clean", 
     "userID":"wDHZv3OL55SIymHkhMUejNleNkx1", 
     "weight":"195" 
     } 
    ], 
    [ 

    ], 
    [ 

    ], 
    [ 
     { 
     "comments":"Front squat comment alpha", 
     "movement":"Front Squat", 
     "userID":"wDHZv3OL55SIymHkhMUejNleNkx1", 
     "weight":"315" 
     } 
    ], 
    [ 

    ], 
    [ 

    ], 
    [ 

    ], 
    [ 

    ], 
    [ 

    ], 
    [ 
     { 
     "comments":"abc", 
     "movement":"Strict Press", 
     "userID":"wDHZv3OL55SIymHkhMUejNleNkx1", 
     "weight":"155" 
     } 
    ] 
] 

これは私がJSON形式で使用している入力されています。ご覧のように、複数の空の配列があります。

これらのアレイをフィルタリングして空のものを削除するにはどうすればよいですか？

Answer 1

Array#filter天然又はlodashの_.filter()を使用し、そして0

Array#filter

var arrs = [[{"comments":"asd","movement":"Back Squat","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"330"}],[{"comments":"asd","movement":"Bench Press","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"100"}],[{"comments":"Comment","movement":"Clean","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"195"}],[],[],[{"comments":"Front squat comment alpha","movement":"Front Squat","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"315"}],[],[],[],[],[],[{"comments":"abc","movement":"Strict Press","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"155"}]]; 
 

 
var result = arrs.filter(function(sub) { 
 
    return sub.length; 
 
}); 
 

 
console.log(result);

Lodashの_.filter()

以外の長さのサブアレイを保ちます

var arrs = [[{"comments":"asd","movement":"Back Squat","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"330"}],[{"comments":"asd","movement":"Bench Press","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"100"}],[{"comments":"Comment","movement":"Clean","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"195"}],[],[],[{"comments":"Front squat comment alpha","movement":"Front Squat","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"315"}],[],[],[],[],[],[{"comments":"abc","movement":"Strict Press","userID":"wDHZv3OL55SIymHkhMUejNleNkx1","weight":"155"}]]; 
 

 
var result = _.filter(arrs, function(sub) { 
 
    return sub.length; 
 
}); 
 

 
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Answer 2

テストが非ゼロ（truthy）長さを有しているかどうかを確認するために順番に各アレイ。そうであれば、新しい配列に入れます。

var array_of_arrays = [[1], [1,1], [], [], [1]]; 
 
var array_of_non_empty_arrays = array_of_arrays.filter((array) => array.length); 
 
console.log(array_of_non_empty_arrays);

Answer 3

トップレベルの配列内のすべての項目が配列されているなら、あなたはisEmpty述語とのrejectをlodashことができます。

let result = _.reject(data, _.isEmpty); 

isEmptyあなたのトップレベルの配列がちょうど空の配列を削除するにはそのような項目を含めることができる場合は、あなただけの空の配列を返すために、新たな機能を構成していることを使用することができますので、他のものの中で、空のオブジェクトのtrueを返しますように

let isEmptyArray = item => _.isArray(item) && _.isEmpty(item); 

let result = _.reject(data, isEmptyArray);