how to sort arrays while ignoring null values in java script-CodePudding

initialArray = [ obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8 ]; // all eight are uniq objects
filterdArray = [ obj2, obj5, obj6, obj8 ]; // varies from 0 to 8

varOrder1 = [ 6, 3, 8, 2, 1, 4, 5, 7 ]
varOrder2 = [ 7, 5, 4, 1, 2, 8, 3, 6 ]

I have a varOrder as input, which is from 1 to 8. It is always 1-8 but in different order as per user wish.

Initially the Array have Obj1 to Obj8, but after filter, the Array may or may not have elements, If it has elements, it varies from 1 to 8.

what am I looking for is if

filterdArray = [ obj2, obj5, obj6, obj8 ]; // and my varOrder is
varOrder = [ 6, 8, 3, 2, 1, 4, 5, 7 ]; // required ouput is like below

FinalObjects = [ obj6, obj8, obj2, obj5 ]

In simple, out of 8 in the order give by user, if some objects are not available skip to next object.

CodePudding user response：

Perform the mapping first, then filter.

const varOrder = [ 6, 8, 3, 2, 1, 4, 5, 7 ];
const initialArray = [ obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8 ];

const orderedArray = varOrder.map((idx) => initialArray[idx - 1]);
// [ obj6, obj8, obj3, obj2, obj1, obj4, obj5, obj7 ]

const filteredArray = orderedArray.filter(obj => obj !== null);
// Assume all objects are null except for 6, 8, 2, and 5.
// [ obj6, obj8, obj2, obj5 ]

CodePudding user response：

Hope this is the expected result. just used a for loop

let obj1 = {name: 'obj1'};let obj2 = {name: 'obj2'};let obj3 = {name: 'obj3'};let obj4 = {name: 'obj4'};let obj5 = {name: 'obj5'};let obj6 = {name: 'obj6'};let obj7 = {name: 'obj7'};let obj8 = {name: 'obj8'}

initialArray = [ obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8 ]; // all eight are uniq objects
filterdArray = [ obj2, obj5, obj6, obj8 ]; // varies from 0 to 8

varOrder1 = [ 6, 3, 8, 2, 1, 4, 5, 7 ];
varOrder2 = [ 7, 5, 4, 1, 2, 8, 3, 6 ];

let finalArr1 = [];
let finalArr2 = [];

const sorter = (varOrder) => {
    let finalArr = []
  for (let i = 0; i < varOrder.length; i  ) {
  
    if (filterdArray.includes(initialArray[varOrder[i]-1])){
        finalArr.push(initialArray[varOrder[i]-1])
    }
   }
   return finalArr;
}       

console.log(sorter(varOrder1))

console.log(sorter(varOrder2))

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