附加/推送到json对象

Question

I'm trying to create the following json object, I want to create the object with the tshirt name, and then after it's been created append a list of sizes to it.

{ tshirt: 'Vintage 80s',
    size: { small: false },
    size: { medium: false },
    size: { large: true }
}

I can create the object easily with these lines of code

var availability = {};
availability.tshirt = "Vintage 80s";

but how would one go about appending each size to the object? this is for a node/express app, so I'd need a pure javascript solution. is there something like a .push for json objects as there as for arrays?

Answer 1

Object keys are unique. You might want to use another object instead:

{ tshirt: 'Vintage 80s',
  size: {
    small: false,
    medium: false,
    large: true
  }
}

You could then access the small size with something like:

availability.size.small

Answer 2

You can't have multiple properties with the same name (like size ), but you can add all size objects to an array:

{ 
    tshirt: 'Vintage 80s',
    sizes: [
        { small: false },
        { medium: false },
        { large: true }
    ]
}

Note: that's not JSON, just a plain JavaScript object literal. JSON is a string notation to represent and exchange data.

Answer 3

You have an object now with duplicate keys (size). I would propose to create another property "sizes" and add an array to it with objects, representing key value pairs for the sizes.

{ tshirt: 'Vintage 80s',
  sizes: [{ small: false },
     { medium: false },
     { large: true }]
}


var availability = {};
availability.tshirt = "Vintage 80s";
availability.sizes = [{ small: false }, { medium: false }, { large: true }]];

Answer 4

You can set it just like how you set the tshirt

//Create an object of sizes
var sizes = {
    small: false,
    medium: false,
    large: true
}

//Create your availability object.
var availability = {};
availability.tshirt = "Vintage 80s";

//Assign the sizes
availability.sizes = sizes;

//Log the results, change out small for medium or large
console.log(availability.sizes.small);