What is regular expression?
A regular expression is a pattern that is used to match character combinations in strings.
The regular expression is the most complicated thing if we don’t understand the basics of it. It is important to know the basics of it. Throughout the software development career, it will be hard to find someone who never used regular expression.
But if we know the basics then it is really easy and smart things to do. Following are some really useful regular expression that we think every developer should know:
The following code snippets are written in Java.
Replace various symbols that are not math symbols, currency signs, or combining characters.
Replace all alphanumeric chanarcters.
inputString.replaceAll("^[a-zA-Z0-9]*$", ""); or inputString.replaceAll("^\w+$", "");
Find the decimal part
const priceStr = '288.35 kr'; priceStr.replace(/\.\d+/, ''); // Output: 288.35 kr
Find email pattern
const email = 'firstname.lastname@example.org'; const isEamil = /^\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$/.test(email); console.log(isEamil); // true
Useful links for about regular expression: