How to remove text from a string?

javascript

regex

string-manipulation

functions

byAnton Shumikhin·Dec 27, 2024

Remove a string segment using .replace():

let result = "Hello World!".replace("World", "");

Behold, result now echoes "Hello !". Goodbye, "World"!

To overwhelm all instances of a substring, we resort to the trusty global flag (/g) within our regular expressions. Here's how:

let catchyPhrase = "apple banana apple";
let result = catchyPhrase.replace(/apple/g, "");

Presto, result is now just a lonely " banana ", with every "apple" exiled.

Surgical text removal

For those provocative specific patterns, regex (regular expressions) rise to the challenge. To preserve only those precious numeric characters in a string:

let cost = "Cost: $25.99";
let cleanCost = cost.replace(/[^0-9\.]+/g, "");

Voila, cleanCost morphs into "25.99". This clever regex eradicates all non-digits except the decimal point.

Unleashing regex magic

Situations might demand more than a mere magic wand, they need a regex sorcerer's spell. To meet your specific needs, brew your custom regex potions:

let mazePath = "/user/profile/data/";
let cleanPath = mazePath.replace(/\/data\/$/, ""); // Removes '/data/' stuck at the path's end

In this sorcery, cleanPath turns out to be "/user/profile", waving goodbye to the trailing '/data/'.

A word of caution

Always value and cross-check the return value of .replace(). JavaScript isn't a regular kingdom—it doesn't amend original strings. Always remember:

let original = "immutable";
let modified = original.replace("imm", "");

// 'original' clings to its identity "immutable"
// while 'modified' rebels into "utable"

Ensure your final fruit matches your desired harvest. A maverick misfit in your regex could sprout unintended results.

Taking the edge off edge cases

When threading through the .replace() labyrinth, remember to escape special characters. Characters like . or * wear special cloaks in the regex realm:

let command = "Seek and replace dots...";
let sanitizedCmd = command.replace(/\./g, "");

// sanitizedCmd is "Seek and replace dots", with dots(.) turned invisible

With non-regex patterns, no cloaks are needed:

let noisyTweet = "Hello #World!";
let peacefulTweet = noisyTweet.replace("#World", "");

// peacefulTweet simply echoes "Hello !"

Hail to JavaScript's treasury of slice() for mining specific sections of a string using start and end markers. Explore the caverns to discover your gold:

let declaration = "Astounding result!";
let fact = declaration.slice(0, -8);

// fact cheerfully broadcasts "Astounding"

For your treasure hunts, online map generators (demos and tests) will guide you to the X of .replace().

Going beyond '.replace()'

While replace() caters to numerous adventures, the wilderness of complex text manipulation seeks custom function heroes:

function removeText(input, toRemove) {
  return input.split(toRemove).join("");
}

let scrollMessage = "remove-remove-";
let cleanedMsg = removeText(scrollMessage, "remove-");

// cleanedMsg is ""— the 'remove-' gremlins vanish!