find-replace

find-replace

Replace or remove multiple items in an array.

Similar to array.prototype.splice() with the following differences:

• splice only operates on one item at a time requiring you to know its index. find-replace will operate on every item satisfying the find function.
• If a function is passed as a replaceWith argument, find-replace will invoke it to compute the replacement value.

Synopsis

import findReplace from 'find-replace'

const colours = ['red', 'white', 'blue', 'white']

const result = findReplace(
  colours,
  colour => colour === 'white',
  'gold'
)

console.log(result)
// [ 'red', 'gold', 'blue', 'gold' ]

If the replaceWith value is a function, it will be invoked with the found item and its result used as the replace value. For example:

const colours = ['red', 'white', 'blue', 'white']

const result = findReplace(
  colours,
  colour => colour === 'red',
  colour => colour.split('')
)

console.log(result)
// [ 'r', 'e', 'd', 'white', 'blue', 'white' ]

Real world examples

Replace with an array of strings

This example explodes combined (-vrf) into individual flags (-v -r -f).

import findReplace from 'find-replace'

const argv = ['-vrf', 'file1.js', 'file2.js']
const combinedShortOptionRe = /^-[^\d-]{2,}$/

const result = findReplace(
  argv,
  arg => combinedShortOptionRe.test(arg),
  arg => {
    return arg
      .slice(1) /* remove initial hypen */
      .split('')
      .map(letter => '-' + letter)
  }
)

console.log(result)

Output:

$ node example/argv.mjs
[ '-v', '-r', '-f', 'file1.js', 'file2.js' ]

Delete found items

If you omit the third replaceWith argument, all found items will be deleted.

import findReplace from 'find-replace'

const fruits = ['apple', 'pear', 'nectarine', 'pineapple', 'peach']
const bad = ['pear', 'pineapple']

const result = findReplace(
  fruits,
  fruit => bad.includes(fruit)
)

console.log(result)

Output:

$ node example/delete.mjs
[ 'apple', 'nectarine', 'peach' ]

API Reference

find-replace

findReplace(array, findFn, [...replaceWith]) ⇒ array ⏏

Kind: Exported function

Param	Type	Description
array	array	The input array
findFn	function	A predicate function which, if returns true causes the current item to be operated on.
[...replaceWith]	any	If not specified, each found value will be removed. If specified, each found value will be replaced with this value. If the replaceWith value is a function, it will be invoked with the found value and its result used as the replace value. If the replaceWith function returns an array, the found value will be replaced with each item in the array (not replaced with the array itself).

Load anywhere

This library is compatible with Node.js, the Web and any style of module loader. It can be loaded anywhere, natively without transpilation.

Node.js (CommonJS):

const findReplace = require('find-replace')

Node.js (ECMAScript Module):

import findReplace from 'find-replace'

Modern browser (ECMAScript Module):

import findReplace from './node_modules/find-replace/dist/index.mjs'

Old browser (adds window.findReplace):

<script nomodule src="./node_modules/find-replace/dist/index.js"></script>

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© 2015-25 Lloyd Brookes <[e-mail]>.

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