javascript – map items and extract items from sub array conditionally

November 26, 2022

How to extract items from a 2d array.

const array = [["1", "3"],["4", "3"]]
const itemToExclude = "3"

Use itemToExclude variable to exclude item from result (in this case 3)

Expected result is ["1", "4"]

const array = [["1", "3"],["4", "3"]]
const itemToExclude = "3"

const result = array.map((item) => {
   return item.map((subitem) => {
      return subitem
      // exclude itemToExclude
      })
    })
        
  console.log(result)

>Solution :

You can use Array flat and filter

const array = [
  ["1", "3"],
  ["4", "3"]
]
const itemToExclude = "3"

const result = array.flat().filter(item => item !== itemToExclude);
console.log(result)

You can also use reduce and inside the callback check if the element is not equals to itemToExclude

const array = [
  ["1", "3"],
  ["4", "3"]
]
const itemToExclude = "3"

const result = array.reduce((acc, curr) => {
  for (let i of curr) {
    if (i !== itemToExclude) {
      acc.push(i)
    }
  }

  return acc;
}, []);

console.log(result)