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# Core Helper Packages

A collection of utility functions for common array and string operations in JavaScript.

## Installation

To use this package, install it via npm:

```bash
npm install core-helper-packages

Usage

You can import the package into your project using CommonJS or ES Modules syntax:

CommonJS

const coreHelper = require('core-helper-packages');

ES Modules

import * as coreHelper from 'core-helper-packages';

API

String Utilities

isString(value)

Checks if the given value is a string.

• Parameters: value (any) - The value to check.
• Returns: boolean - true if the value is a string, otherwise false.

Array Utilities

isArray(value)

Checks if the given value is an array.

• Parameters: value (any) - The value to check.
• Returns: boolean - true if the value is an array, otherwise false.

isNull(value)

Checks if the given value is null.

• Parameters: value (any) - The value to check.
• Returns: boolean - true if the value is null, otherwise false.

isUndefined(value)

Checks if the given value is undefined.

• Parameters: value (any) - The value to check.
• Returns: boolean - true if the value is undefined, otherwise false.

isNullOrUndefined(value)

Checks if the given value is either null or undefined.

• Parameters: value (any) - The value to check.
• Returns: boolean - true if the value is null or undefined, otherwise false.

isArrayEmpty(arr)

Checks if an array is empty.

• Parameters: arr (Array) - The array to check.
• Returns: boolean - true if the array is empty, otherwise false.
• Throws: TypeError - If the input is not an array.

getArrayLength(arr)

Gets the length of an array.

• Parameters: arr (Array) - The array to get the length of.
• Returns: number - The length of the array.
• Throws: TypeError - If the input is not an array.

firstElement(arr)

Retrieves the first element of an array.

• Parameters: arr (Array) - The array to get the first element from.
• Returns: The first element of the array.
• Throws: TypeError - If the input is not an array.

lastElement(arr)

Retrieves the last element of an array.

• Parameters: arr (Array) - The array to get the last element from.
• Returns: The last element of the array, or undefined if the array is empty.
• Throws: TypeError - If the input is not an array.

pushElement(arr, element)

Adds an element to the end of an array.

• Parameters:
  • arr (Array) - The array to modify.
  • element (any) - The element to add.
• Returns: The array with the new element added.
• Throws: TypeError - If the first argument is not an array.

popElement(arr)

Removes the last element from an array.

• Parameters: arr (Array) - The array to modify.
• Returns: The array with the last element removed.
• Throws: TypeError - If the input is not an array.

sumArray(arr)

Calculates the sum of all numeric values in an array.

• Parameters: arr (Array) - The array containing numeric values.
• Returns: number - The sum of the numeric values in the array.
• Throws: TypeError - If the input is not an array or contains non-numeric values.

averageArray(arr)

Calculates the average of all numeric values in an array.

• Parameters: arr (Array) - The array containing numeric values.
• Returns: number - The average of the numeric values in the array.
• Throws: TypeError - If the input is not an array or contains non-numeric values.

maxArray(arr)

Finds the maximum value in an array.

• Parameters: arr (Array) - The array to search.
• Returns: number - The maximum value in the array.
• Throws: TypeError - If the input is not a non-empty array.

minArray(arr)

Finds the minimum value in an array.

• Parameters: arr (Array) - The array to search.
• Returns: number - The minimum value in the array.
• Throws: TypeError - If the input is not a non-empty array.

mapArray(arr, callback)

Applies a function to each element of the array and returns a new array.

• Parameters:
  • arr (Array) - The array to map over.
  • callback (Function) - The function to apply to each element.
• Returns: A new array with each element transformed by the callback function.
• Throws: TypeError - If the first argument is not an array or the second argument is not a function.

filterArray(arr, predicate)

Filters elements of the array based on a predicate function and returns a new array.

• Parameters:
  • arr (Array) - The array to filter.
  • predicate (Function) - The function to test each element.
• Returns: A new array with elements that pass the predicate function.
• Throws: TypeError - If the first argument is not an array or the second argument is not a function.

flatArray(arr)

Flattens a nested array into a single-level array.

• Parameters: arr (Array) - The nested array to flatten.
• Returns: The flattened array.
• Throws: TypeError - If the input is not an array.

uniqueArray(arr)

Removes duplicate values from an array.

• Parameters: arr (Array) - The array from which to remove duplicates.
• Returns: The array with duplicate values removed.
• Throws: TypeError - If the input is not an array.

Examples

Here are some example usages for each function:

const coreHelper = require('core-helper-packages');

// String Utilities
console.log(coreHelper.isString("hello")); // true

// Array Utilities
const arr = [1, 2, 3, 4];
console.log(coreHelper.isArray(arr)); // true
console.log(coreHelper.isArrayEmpty([])); // true
console.log(coreHelper.getArrayLength(arr)); // 4
console.log(coreHelper.firstElement(arr)); // 1
console.log(coreHelper.lastElement(arr)); // 4
console.log(coreHelper.pushElement(arr, 5)); // [1, 2, 3, 4, 5]
console.log(coreHelper.popElement(arr)); // [1, 2, 3, 4]
console.log(coreHelper.sumArray(arr)); // 10
console.log(coreHelper.averageArray(arr)); // 2.5
console.log(coreHelper.maxArray(arr)); // 4
console.log(coreHelper.minArray(arr)); // 1
console.log(coreHelper.mapArray(arr, x => x * 2)); // [2, 4, 6, 8]
console.log(coreHelper.filterArray(arr, x => x > 2)); // [3, 4]
console.log(coreHelper.flatArray([[1], [2, 3], [4]])); // [1, 2, 3, 4]
console.log(coreHelper.uniqueArray([1, 2, 2, 3, 4, 4])); // [1, 2, 3, 4]