JavaScript：在包含特定字符串的属性的数组中查找对象

Question

In JavaScript, if you have an array of objects with a format like:

Persons = {
  'First Name': 'Dark',
  'Last Name': 'Defender',
  Age: 26
}

And you need to go through each to find the persons with a certain string in their last name, for example: 'der'.

How would you use the .find() to find and return the persons with 'der' in their last name?

I have tried:

personArray = persons.find(({[“Last Name”]}) => “Last Name” === ‘der’);

It works for age but I can't seem to get the syntax right for multiple word key like “Last Name”.

Answer 1

You could use Array#filter to filter out all of these entries where Last Name includes "der" .

 const arr = [ { "First Name": 'Dark', "Last Name": 'Defender', Age: 26}, { "First Name": 'Dark', "Last Name": 'Abc', Age: 26}, { "First Name": 'Dark', "Last Name": 'Xyz', Age: 26}, ]; const res = arr.filter(({ ["Last Name"]: name }) => name && name.includes('der')); console.log(res);

Answer 2

You can use .filter and .indexOf to check for the substring in each person's last name:

 const persons = [ { 'First Name': 'Dark', 'Last Name': 'Defender', Age: 26}, { 'First Name': 'Ben', 'Last Name': 'Robbins', Age: 22}, { 'First Name': 'John', 'Last Name': 'Beans', Age: 23} ]; const personArray = persons.filter(person => person['Last Name'] && person['Last Name'].indexOf('der') !== -1 ); console.log(personArray);

Answer 3

You can use filter and includes methods

 const persons = [ { "First Name": "Dark", "Last Name": "Defender", Age: 26 }, { "First Name": "Carlos", "Last Name": "Defback" }, { "First Name": "Carlos", "Last Name": "None"} ]; const foundPersons = persons.filter(person => person["Last Name"].includes("Def") ); console.log('foundPersons: ', foundPersons)

Answer 4

As you said we have an array of the object(persons) like this:-

const arr = [
 { “First Name”: “Dark”, “Last Name”: “Defender”, Age: 26},
 { “First Name”: “Dark”, “Last Name”: “Defender”, Age: 26},
 .
 .
 . etc
]

// do this
const matchingObj = arr.find(el => el["Last Name"].endsWith("der")); // returns first occurence
console.log(matchingObj)