CODEWITHSUNDEEP
javascriptarraysalgorithmlogical-operators
Dhaval Jardosh
Dhaval Jardosh

Reputation: 7299

Logical OR in an Array

Here is where I want to implement my OR

return bigData.country==["US"||"JP"] && (bigData.description=="iPhone 4S")

[ A || B || C || ... ] && [ X || Y || Z ||....]

As you can see above, I am returning objects, if the value of key of object bigData.country is either US or JP, AND bigData.description is either iPhone 4S, can also be more devices.

I'm able to get the desired result, by

return (bigData.country=="US"||bigData.country=="JP") && (bigData.description=="iPhone 4S")

But as I can have convenience to add and remove from an Array, I am trying to use an array. Suggestion to use something different is also welcomed.

If you want to play around with my code here is REPL

Upvotes: 3

Views: 2937

Answers (6)

vol7ron
vol7ron

Reputation: 42109

Using Array.prototype.includes is most likely what you're after:

let valid = {
  countries: ['US', 'JP'],
  description: 'iPhone 4S'
};
let dataset = [{
  country: 'US',
  description: 'iPhone 4S',
  expected: true
}, {
  country: 'JP',
  description: 'iPhone 4S',
  expected: true
}, {
  country: 'AA',
  description: 'iPhone 4S',
  expected: false
}, {
  country: 'US',
  description: 'iPhone',
  expected: false
}]

// iterate over data values
dataset.forEach(data => {
  let is_valid = valid.countries.includes(data.country) && valid.description == data.description;
  
  console.log(
    `Country:"${data.country}"`,
    `Description:"${data.description}"`,
    `Expected:${data.expected}`,
    `Got:${is_valid}`
  );
});

Upvotes: 1

Vilx-
Vilx-

Reputation: 106920

With an Array:

return ['US','JP'].indexOf(bigData.country) >= 0 &&
       ['iPhone 4S'].indexOf(bigData.description) >= 0;

With an object (possibly better performance):

return {'US': true,'JP': true}[bigData.country] &&
       {'iPhone 4S': true}[bigData.description];

As pointed out by @ibrahim mahrir, the object approach doesn't always work. For example, if bigData.country=='toString'. This is because Javascript objects come with a default baggage of methods from their default Object prototype. In a real world scenario the likelihood of running afoul of this problem is negligible, but if you want to do it really really properly, there are two options:

1 - Use hasOwnProperty():

return {'US': true,'JP': true}.hasOwnProperty(bigData.country) &&
       {'iPhone 4S': true}.hasOwnProperty(bigData.description);

2 - Use an object WITHOUT a prototype. This is more verbose to set up, but also more convenient to use. You can also write a trivial method that converts a regular object to a prototype-less object.

var countries = new Object(null);
countries['US'] = true;
countries['JP'] = true;

var descriptions = new Object(null);
descriptions['iPhone 4S'] = true;

return countries[bigData.country] &&
       descriptions[bigData.description];

Upvotes: 2

Nina Scholz
Nina Scholz

Reputation: 386654

You could use an object as data structure for testing:

var countries = {
        US: true,
        JP: true
    };


return countries[bigData.country] && ...

Upvotes: 1

cнŝdk
cнŝdk

Reputation: 32145

You can use Array#some() method like this:

ES6:

return ['US','JP'].some(val => bigData.country === val) && ['iPhone 4S'].some(v => bigData.description === v);

ES5:

return ['US','JP'].some(function(val){return bigData.country === val}) && ['iPhone 4S'].some(function(v){return bigData.description === v});

Demo:

let bigData = {
  country: 'JP',
  description: 'iPhone 4S'
};

console.log(['US', 'JP'].some(val => bigData.country === val) && ['iPhone 4S'].some(v => bigData.description === v));

Upvotes: 2

Ori Drori
Ori Drori

Reputation: 191996

Use an ES6 Set (REPL):

const countriesToKeep = new Set(['GP', 'US']);

console.log(countriesToKeep.has('UK'));

console.log(countriesToKeep.has('GP'));

Upvotes: 1

ibrahim mahrir
ibrahim mahrir

Reputation: 31692

You can use Array.prototype.indexOf (to be != -1) like this:

return ["US", "JP"].indexOf(bigData.country) !== -1 && ["X", "Y", "Z"].indexOf(bigData.description) !== -1;

Or in ES6, you can use Array.prototype.includes like:

return ["US", "JP"].includes(bigData.country) && ["X", "Y", "Z"].includes(bigData.description);

Upvotes: 3

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