Posted on Aug 4 JavaScript functions are blocks of code that perform a specific task or calculation. They are a fundamental building block of JavaScript programming and play a crucial role in creating dynamic and interactive web applications.Functions can also be assigned to variables, allowing them to be treated as first-class objects in JavaScript. This enables functions to be passed as arguments to other functions or returned from functions, supporting powerful functional programming techniques.Higher-order Function is a concept in programming where a function accepts another function as an argument and returns it's function as the result. In other words treats other functions as first-class citizens allowing them to be used just like other data type, like string or number. A nice example of higher-order function is the setTimeOut function, That schedules a particular function to execute after a specified time delay.Other examples of higher-order function are reduce, sort, find, some, forEach etc.Higher-order functions are flexible concept, and they enable several useful programming patterns, such as functional programming. By accepting or returning functions, higher-order functions enable code reusability, modularity, and the separation of concerns.Let's go through each line of code and explain its purposeonWord function receives str as an argumentInside the function, it uses the 'replace' method with a regular expression '/ /g' to replace all spaces with hyphens '-'The 'toLowerCase' method is then used to convert the entire string to lowercase.The upperFirstWord function takes a string tri as an argument.Inside the function, it uses the split method to split the input string into an array of words, using a space ' ' as the separator.The destructuring assignment [first, ...others] is used to extract the first word from the array and store the remaining words in the others array.The toUpperCase method is used to convert the first word to uppercase.The join method is then used to combine the modified first word with the remaining words, separated by spaces.Here the transform function can be referred as the higher-order functionThe transform function takes two arguments: fri and fn.fri is expected to be a string, and fn is expected to be a function that can transform the string.Inside the function, it first logs the original string (fri) to the console.It then invokes the function fn (which should be a transformation function) with fri as the argument and logs the transformed result to the console.Finally, it logs the name of the transformation function (fn) to the console.This line calls the transform function.It passes the string "Javascript is the best!" as the first argument (fri) and the function upperFirstWord as the second argument (fn).The transform function will then log the original and transformed strings to the console, along with the name of the transformation function.This line calls the transform function again, but this time with different arguments.It passes the string 'javascript is the best!' as the first argument (fri) and the function oneWord as the second argument (fn).The transform function will once again log the original and transformed strings to the console, along with the name of the transformation functionIn conclusion, higher-order functions are powerful constructs in programming languages that enable functions to be treated as first-class citizens. They can accept other functions as arguments and return functions as results. This flexibility allows for code modularity, reusability, and separation of concerns, making higher-order functions a fundamental tool for writing concise, maintainable, and versatile code.Templates let you quickly answer FAQs or store snippets for re-use. Are you sure you want to hide this comment? It will become hidden in your post, but will still be visible via the comment's permalink. Hide child comments as well Confirm For further actions, you may consider blocking this person and/or reporting abuse Karishma Shukla - Jul 28 Adrian Sandu - Jul 4 Shilleh - Jul 5 Ibrahim Enemona Abdulrasheed - Jul 17 Once suspended, raymondkingjnr will not be able to comment or publish posts until their suspension is removed. Once unsuspended, raymondkingjnr will be able to comment and publish posts again. Once unpublished, all posts by raymondkingjnr will become hidden and only accessible to themselves. 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