allow for empty strings in arrays, for ljharb#7

README.md

@@ -97,6 +97,15 @@ Qs.parse('a[1]=b&a[15]=c');
 // { a: ['b', 'c'] }
 ```
 
+Note that an empty string is also a value, and will be preserved:
+
+```javascript
+Qs.parse('a[]=&a[]=b');
+// { a: ['', 'b'] }
+Qs.parse('a[0]=b&a[1]=&a[2]=c');
+// { a: ['b', '', 'c'] }
+```
+
 **qs** will also limit specifying indices in an array to a maximum index of `20`. Any array members with an index of greater than `20` will
 instead be converted to an object with the index as the key:
 
@@ -117,4 +126,4 @@ You can also create arrays of objects:
 ```javascript
 Qs.parse('a[][b]=c');
 // { a: [{ b: 'c' }] }
-```
+```

lib/utils.js

@@ -115,7 +115,7 @@ exports.compact = function (obj) {
 
                 for (var i = 0, l = obj[key].length; i < l; i++) {
                     if (obj[key].hasOwnProperty(i) &&
-                        obj[key][i]) {
+                        obj[key][i] !== null) {
 
                         compacted[key].push(obj[key][i]);
                     }

test/parse.js

@@ -184,6 +184,13 @@ describe('#parse', function () {
         done();
     });
 
+    it('allows for empty strings in arrays', function (done) {
+
+        expect(Qs.parse('a[]=b&a[]=&a[]=c')).to.deep.equal({ a: ['b', '', 'c'] });
+        expect(Qs.parse('a[0]=b&a[1]=&a[2]=c&a[19]=')).to.deep.equal({ a: ['b', '', 'c', ''] });
+        done();
+    });
+
     it('should compact sparse arrays', function (done) {
 
         expect(Qs.parse('a[10]=1&a[2]=2')).to.deep.equal({ a: ['2', '1'] });