Regular Expression - Language-Specific Syntax

Language-Specific Syntax

Python

import re
 
# Match
match = re.search(r'\d+', 'Phone: 123-456')
if match:
    print(match.group()) # "123"
 
# Find all
numbers = re.findall(r'\d+', 'Phone: 123-456-7890')
print(numbers) # ['123', '456', '7890']
 
# Replace
text = re.sub(r'\d+', 'X', 'Phone: 123')
print(text) # "Phone: X"
 
# Split
parts = re.split(r'[-/]', '2024-01-15')
print(parts) # ['2024', '01', '15']
 
# Compile for reuse
pattern = re.compile(r'\d+')
result = pattern.findall('123 and 456')

JavaScript

// Match
const match = '123-456'.match(/\d+/);
console.log(match[0]); // "123"
 
// Find all
const numbers = '123-456-7890'.match(/\d+/g);
console.log(numbers); // ['123', '456', '7890']
 
// Test
const isValid = /^\d{3}-\d{4}$/.test('123-4567');
console.log(isValid); // true
 
// Replace
const text = 'Phone: 123'.replace(/\d+/, 'X');
console.log(text); // "Phone: X"
 
// Split
const parts = '2024-01-15'.split(/[-/]/);
console.log(parts); // ['2024', '01', '15']

SQL (Basic)

-- LIKE operator (limited regex)
SELECT * FROM users WHERE email LIKE '%@gmail.com';
 
-- REGEXP (MySQL)
SELECT * FROM users WHERE email REGEXP '^[a-z]+@[a-z]+\\.com$';
 
-- SIMILAR TO (PostgreSQL)
SELECT * FROM users WHERE email SIMILAR TO '[a-z]+@[a-z]+\\.com';