I am trying to find the best way to check whether an object key is present inside multiple objects present in an array which will provide a boolean as output [{alert:hi},{alert:bye},{}]

From the above example basically what I am trying to achieve is if any one object is missing the alert object key the output should be as false or anything

CodePudding user response：

You can iterate your array with every(). Something like this:

const objects = [{alert:'hi'},{alert:'bye'},{}];
const every = objects.every(obj => obj.hasOwnProperty('alert'));
console.log(every);

CodePudding user response：

You can use the Array#some method and check if at least one element is undefined

const isAlertMissing = (array) => array.some(elem => elem.alert === undefined)

const objs1 = [{alert: "foo"},{alert: "foo"},{}]
const objs2 = [{alert: "foo"},{alert: "foo"}]

console.log(isAlertMissing(objs1))
console.log(isAlertMissing(objs2))

CodePudding user response：

You can use every to check all items and some with Object.keys for finding a key in the inner objects.

const data = [{alert:"hi"},{alert:"bye"},{}]
const result = data.every(item => Object.keys(item).some(key => key === "alert"));

console.log(result) //false

EDIT

some with Object.keys is kind of roundabout, so we can use hasOwnProperty instead.

const data = [{alert:"hi"},{alert:"bye"},{}]
const result = data.every(item => item.hasOwnProperty("alert"));

console.log(result) //false

CodePudding user response：

Array#some will succeed as soon a match is found, making it more efficient than Array#every.

const test = (data, propName) => 
  !(data.some((el) => !el.hasOwnProperty(propName)))

const data1 = [ {alert:'hi'}, {alert:'bye'}, {}]
const data2 = [ {alert:'hi'}, {alert:'bye'}]

console.log(test(data1, 'alert')) // false
console.log(test(data2, 'alert')) // true

Or:

const test = (data, propName) => {  
  for(let el of data) {
    if(!el.hasOwnProperty(propName)) 
      return false 
  }

  return true
}

const data1 = [ {alert:'hi'}, {alert:'bye'}, {}]
const data2 = [ {alert:'hi'}, {alert:'bye'}]

console.log(test(data1, 'alert')) // false
console.log(test(data2, 'alert')) // true