@dongskyler/helpers.js

Homepage: https://github.com/dongskyler/helpers.js

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Table of contents

• Description
• Functions
  • inputOutput
    • listFilesInDirSync()
    • loadFile()
    • readPipeWrite()
    • writeToFile()
  • others
    • runFuncsWithArgs()
    • valOfKeysAndIndices()
  • sort
    • comparatorLexic()
    • comparatorNumeric()
    • bubbleSort()
    • mergeSort()
    • partialSort()

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Description

This is a collections of JavaScript and TypeScript helper functions.

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Functions

inputOutput

• listFilesInDirSync()

  listFilesInDirSync(dir[, ext, removeExt])

  • Parameters
    • dir: string (Positional, required)
      • Path to directory.
    • ext: string | null (Positional, optional)
      • Filter by file extension.
    • removeExt: boolean (Positional, optional)
      • Remove the file extension from the filename string.
  • Return value: string[] | null
    • An array of filenames in a directory.

• loadFile()

• readPipeWrite()

• writeToFile()

others

• runFuncsWithArgs()

  runFuncsWithArgs(funcs[, args, spread])

  • Run an array of functions with the same set of argument(s)
  • Parameters
    • funcs: ((...args: any | any[] | null) => any)[] (Positional, required)
      • An array of functions.
    • args: any | any[] | null = null (Positional, optional)
      • An array of arguments. Each element of the array will be presented to each function.
    • spread: boolean (Positional, optional)
      • If args is an array of arrays, you can choose to expand each sub-array with the spread operator.
      • Default is false.
  • Return value: any[]
    • An array of return values from functions

• valOfKeysAndIndices()

  valOfKeysAndIndices(obj[, key0[, key1[, ...keyN]]])

  • Returns the value in an array or an object (or you call it JSON, a hash map or a dictionary) given the series of indices and/or keys pointing to the value.
  • Parameters
    • obj: any (Positional, required)
      • An array, an object (or you call it JSON, a hash map or a dictionary) or a combination.
      • The first index or key pointing to the value is required.
    • keyN: string | number | null (Positional, optional)
      • An arbitrary number of indices and/or keys pointing to the value.
      • For example, if x = {name: 'Tom'}, to fetch value 'Tom', use valOfKeysAndIndicies(x, 'name'). If y = { key0: [{ key1: [3.142, 6.626,] },] }, to fetch 6.626, use valOfKeysAndIndicies(y, 'key0', 0, 'key', 1).
  • Return value: any
    • The value from the given indices/keys.

sort

• comparatorLexic()

  comparatorLexic([{key = [], ignoreCase = false, descending = false})

  • Compare function for comparing lexicographic order.
  • Parameters
    • ignoreCase: boolean (Named, optional)
      • Ignore the case of the given string.
      • Default is false.
    • descending: boolean (Named, optional)
      • Ascending or descending order.
      • Default is false, that is, ascending order.
    • keyN: string | number | null (Positional, optional)
      • An arbitrary number of indices and/or keys pointing to the value for comparison.
      • For example, if x = {name: 'Tom'}, use comparatorLexic('name') to fetch value 'Tom' for comparison. If x = { key0: [{ key1: [Earth, Mars,] },] }, to fetch Mars for comparison, use comparatorLexic('key0', 0, 'key', 1).
      • See keyN in valOfKeysAndIndices for more details.
      • Default is null.
  • Return value: function
    • Function (x: any, y: any) => number
      • Return value: number
        • -1 if a should placed before b.
        • 0 if a and b are equal.
        • 1 if a should be placed after b.

• comparatorNumeric()

  comparatorNumeric([{key = [], ignoreSign = false, descending = false})

  • Compare function for comparing numerical order.
  • Parameters
    • keyN: string | number | null (Positional, optional)
      • An arbitrary number of indices and/or keys pointing to the value for comparison.
      • If x = { key0: [{ key1: [3.142, 6.626,] },] }, to fetch 6.626 for comparison, use comparatorLexic('key0', 0, 'key', 1).
      • See keyN in valOfKeysAndIndices for more details.
      • Default is null.
    • ignoreSign: boolean (Named, optional)
      • Ignore the sign of the number, i.e. use the absolute value for comparison.
      • Default is false.
    • descending: boolean (Named, optional)
      • Ascending or descending order.
      • Default is false, that is, ascending order.
  • Return value: function
    • Function (a: any, b: any) => number
      • Return value: number
        • -1 if a should placed before b.
        • 0 if a and b are equal.
        • 1 if a should be placed after b.

• bubbleSort()

  bubbleSort(arr[, compareFunction, k])

  • Bubble sort algorithm. Stable.
  • Parameters
    • arr: any[] (Positional, required)
      • An array to be sorted.
    • compareFunction: (a: any, b: any) => number (Positional, optional)
      • Compare function.
      • Default is comparatorLexic().
    • k: number (Positional, optional)
      • Partially sort the array to get the first k sorted elements
  • Return value: any[]
    • A sorted array.

• mergeSort()

  mergeSort(arr[, compareFunction])

  • Merge sort algorithm. Stable.
  • Parameters
    • arr: any[] (Positional, required)
      • An array to be sorted.
    • compareFunction: (a: any, b: any) => number (Positional, optional)
      • Compare function.
      • Default is comparatorLexic().
  • Return value: any[]
    • A sorted array.

• partialSort()

  partialSort(arr[, compareFunction, k])

  • Partially sort the array to get the first k sorted elements, given the compare function.