angular array equals array code example

Example 1: best way compare arrays javascript

// To compare arrays (or any other object):
// Simple Array Example:
const array1 = ['potato', 'banana', 'soup']
const array2 = ['potato', 'orange', 'soup']

array1 === array2;
// Returns false due to referential equality
JSON.stringify(array1) === JSON.stringify(array2);
// Returns true 


// Another Example:
const deepArray1 = [{test: 'dummy'}, [['woo', 'ya'], 'weird']]
const deepArray2 = [{test: 'dummy'}, [['woo', 'ya'], 'weird']]

deepArray1 === deepArray2;
// Returns false due to referential equality
JSON.stringify(deepArray1) === JSON.stringify(deepArray2);
// Returns true

Example 2: comparing array of objects in javascript

// IN THIS EXAMPLE WE HAVE GROUP INSERTS - DATA TO BE ADDED TO DB
// TO INSERT INTO DB EACH GROUP NAME MUST BE THE MATCHING ID
// CONATCT NAME MUST ALSO BE MATCHING ID
// THE CODE BELOW SHOWS HOW TO TRAVERSE THROGUH TWO ARRAYS AND COMPARE / ADD VALES

const groupInserts = [ { groups: [ 'Chess', 'Science', 'German' ], name: 'Ian Smith' },
  { groups: [ 'Swimming' ], name: 'Jenny Smith' },
  { groups: [ 'Tennis' ], name: 'Susan Jones' },
  { groups: [ 'Coding', 'Science' ], name: 'Judy Davis' } ]

const nameAndIdsFromDB = [ { name: 'Parent_1', id: 1 },
{ name: 'Parent_2', id: 2 },
{ name: 'Ian Smith', id: 99 },
{ name: 'Jenny Smith', id: 100 },
{ name: 'Susan Jones', id: 101 },
{ name: 'Judy Davis', id: 102 } ]

const groupnameAndIdsFromDB = [ { name: 'Debugging', id: 1 },
{ name: 'React', id: 2 },
{ name: 'New record with no people', id: 3 },
{ name: 'New record with people', id: 4 },
{ name: 'Chess', id: 12 },
{ name: 'Science', id: 13 },
{ name: 'German', id: 14 },
{ name: 'Swimming', id: 15 },
{ name: 'Tennis', id: 16 },
{ name: 'Coding', id: 17 } ]

let groupNamesWithIds = [];
groupInserts.forEach(data => {
    if (data.groups) {
         data.groups.map(e => {
                let obj = {};
                obj.group = e;
                obj.name = data.name
                groupNamesWithIds.push(obj);
        })
    }
})


let addedMessageGroupIds = [];
groupNamesWithIds.forEach(data => {
  groupnameAndIdsFromDB.map(e => {
    if (e.name === data.group) {
      addedMessageGroupIds.push({group: data.group, name: data.name, messages_individual_groups_id: e.id})
    }
  })
})

let addedContactIds = [];
addedMessageGroupIds.forEach(data => {
  nameAndIdsFromDB.map(e => {
    if (e.name === data.name) {
      addedContactIds.push({messages_individual_groups_id: data.messages_individual_groups_id, contact_id: e.id, created_at: Date.now()})
    }
  })
})