How to sort an array based on a boolean prop and a name prop?

Question

I have an array of objects that look like this:

[
  {
    name: s1,
    isDefault: false
  },
  {
    name: s2,
    isDefault: true
  },
  {
    name: s3,
    isDefault: false
  }
]

I want to sort this array so that the element with isDefault: true is placed first, and have the rest follow this object in alphabetical order.

In other words:

[
  {
    name: s2,
    isDefault: true
  },
  {
    name: s1,
    isDefault: false
  },
  {
    name: s3,
    isDefault: false
  }
]

I know how to accomplish the first condition:

objPanoramas.sort((a, b) => {
  return a.isDefault < b.isDefault
})

How can I integrate the second condition?

score 2 · Answer 1 · answered Aug 16 '16 at 06:49

2

objPanoramas.sort((a, b) => {
  if (a.isDefault == b.isDefault) {
    name1 = a.name;
    name2 = b.name;
    return name1<name2?-1:(name1>name2?1:0)
  }
  return a.isDefault < b.isDefault
})

answered Aug 16 '16 at 06:49

Andy Dunnings

136
6

Vanojx1 · Accepted Answer · 2016-08-16T07:32:22.070

2

try this

objPanoramas = [{
  name: "s1",
  isDefault: false
},{
  name: "s1",
  isDefault: true
}, {
  name: "s2",
  isDefault: true
}, {
  name: "s3",
  isDefault: false
}]


objPanoramas.sort((a, b) => {
  if ((a.isDefault && b.isDefault) || (!a.isDefault && !b.isDefault)) {
    return a.name.localeCompare(b.name)
  }else{
    return !a.isDefault
  }
})

console.log(objPanoramas);

edited Aug 16 '16 at 07:32

answered Aug 16 '16 at 07:03

Vanojx1

5,574
2
23
37

You should return [positive, zero or negative value from callback](http://www.w3schools.com/jsref/jsref_sort.asp). Your solution would work because of automatic type conversion, but it's not the best practice. – Krzysztof Atłasik Aug 16 '16 at 07:23
I'll edit my answer based on your suggestion... thanks – Vanojx1 Aug 16 '16 at 07:30
I came out with this: `objPanoramas.sort((a, b) => { if (a.isDefault !== b.isDefault) { return a.isDefault < b.isDefault } return a.name > b.name })` Does it do the same as your code? – alexchenco Aug 16 '16 at 07:30
basically yes, but as suggested by @yariash compare the strings using the proper comparison function – Vanojx1 Aug 16 '16 at 07:36

score 1 · Answer 3 · answered Aug 16 '16 at 06:49

You should return positive value, zero or negative from callback of sort:

objPanoramas.sort((a, b) => {
     if(a.isDefault == b.isDefault) {
         return a.name.localeCompare(b.name); //in case both values are equal do alphabetical sort
     } else if(a.isDefault) {
          return 1; //else if a.isDefault is true return positive value.
     }
})

score 1 · Answer 4 · edited May 23 '17 at 10:33

1

This is exactely what you need:

https://stackoverflow.com/a/4576720/6482090

As you can see into this post the solution is to check both value inside your sort().

Look at the example on that post!

edited May 23 '17 at 10:33

Community

1
1

answered Aug 16 '16 at 06:50

greenseed

509
5
10

How to sort an array based on a boolean prop and a name prop?

4 Answers4