JavaScript:
Searching and replacing text
How to:
In JavaScript, String.prototype.replace() is the go-to. Pass a string or regex and the replacement. Here’s the quick and dirty:
let str = "I love to code in JavaScript!";
let newStr = str.replace("JavaScript", "TypeScript");
console.log(newStr); // Outputs: I love to code in TypeScript!
Now, with regex for global replaces:
let story = "The quick brown fox jumps over the lazy dog. The fox is clever.";
let newStory = story.replace(/fox/g, "cat");
console.log(newStory); // Outputs: The quick brown cat jumps over the lazy dog. The cat is clever.
Deep Dive
Looking back, String.prototype.replace() has been in JS since the early days—Netscape 2 early. Now, ES6 brought us template literals and arrow functions, which spiced things up with more concise and readable code using regex.
Alternatives? Sure. If you’re working with large-scale text processing, you might sidestep into Node.js streams or leverage external libraries to handle complex patterns, efficiency, and performance.
As for implementation, replace() alone is simple. But regex patterns can get wild. Start easy, learn the special characters (. matches any char, * for repeating patterns), and test with tools like regex101.
See Also
- MDN replace documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
- Regex101 for testing expressions: https://regex101.com/
- JavaScript info on regex: https://javascript.info/regexp-introduction