How to check if an object with specific key-value exists

Question

i have a response from the API something like this:

var res = [{data: "street_number", label: "121"},
           {data: "route", label: "Ladbroke Grove"},
           {data: "postal_town", label: "London"},
           {data: "administrative_area_level_1", label: "England"},
           {data: "postal_code", label: "W11 1PN"}]

but sometimes like so:

var res = [{data: "route", label: "Ladbroke Grove"},
           {data: "postal_town", label: "London"},
           {data: "administrative_area_level_1", label: "England"},
           {data: "postal_code", label: "W11 1PN"}]

so it missed the "street_number".

Now how can i check if that specific data-value exists, regardless of what label-value is? And i don't wanna check on res.length either, since the length of it is really different.

Answer 1

You need to iterate over the dataset and check for the specific value you need.

var hasStreetNumber = res.find((x) => x.data === 'street_number') !== undefined;

Is one of many ways you check if the value you're looking for exists in the list.

Answer 2

This is an array of JS objects. A simple option would be to iterate through the array and check for the presence of a certain String in each Objects' data value. The following would iterate through an array and return true if a data value in the array matches the input:

    function checkDataValue(array, dataValue) {
      let contains = false;
      for (i = 0; i <  array.length; i++) {
        if (array[i]['data'] === dataValue) {
          contains = true;
        }
      }
    return contains;
    }