Practice 50 PHP Regular Expression Programming Questions

Practice 50 PHP Regular Expression Programming Questions

Q1: Write a regular expression to check if a string contains only digits.  
Input: isOnlyDigits("12345")  
Expected Output:  
True

Q2: Write a regular expression to check if a string contains only alphabets.  
Input: isOnlyAlphabets("HelloWorld")  
Expected Output:  
True

Q3: Write a regular expression to check if a string contains a specific word "PHP".  
Input: containsWord("I love PHP")  
Expected Output:  
True

Q4: Write a regular expression to validate an email address.  
Input: validateEmail("example@test.com")  
Expected Output:  
True

Q5: Write a regular expression to check if a string contains only lowercase letters.  
Input: isLowercase("hello")  
Expected Output:  
True

Q6: Write a regular expression to check if a string starts with a digit.  
Input: startsWithDigit("123abc")  
Expected Output:  
True

Q7: Write a regular expression to validate a phone number (format: 123-456-7890).  
Input: validatePhoneNumber("123-456-7890")  
Expected Output:  
True

Q8: Write a regular expression to find all words in a string.  
Input: findWords("Learn PHP with examples")  
Expected Output:  
["Learn", "PHP", "with", "examples"]

Q9: Write a regular expression to replace all spaces in a string with underscores.  
Input: replaceSpaces("PHP is fun")  
Expected Output:  
PHP_is_fun

Q10: Write a regular expression to extract numbers from a string.  
Input: extractNumbers("Order123 contains 45 items")  
Expected Output:  
[123, 45]

Q11: Write a regular expression to check if a string ends with ".com".  
Input: endsWithCom("example.com")  
Expected Output:  
True

Q12: Write a regular expression to validate a date in the format YYYY-MM-DD.  
Input: validateDate("2023-12-29")  
Expected Output:  
True

Q13: Write a regular expression to count the number of vowels in a string.  
Input: countVowels("Hello World")  
Expected Output:  
3

Q14: Write a regular expression to find all capital letters in a string.  
Input: findCapitalLetters("Hello World")  
Expected Output:  
["H", "W"]

Q15: Write a regular expression to check if a string is a valid hexadecimal color code.  
Input: isHexColor("#FF5733")  
Expected Output:  
True

Q16: Write a regular expression to validate a password with at least 8 characters, one uppercase letter, one lowercase letter, and one digit.  
Input: validatePassword("Passw0rd")  
Expected Output:  
True

Q17: Write a regular expression to split a string by commas.  
Input: splitByComma("PHP,Java,Python")  
Expected Output:  
["PHP", "Java", "Python"]

Q18: Write a regular expression to check if a string is a valid IP address.  
Input: isIPAddress("192.168.1.1")  
Expected Output:  
True

Q19: Write a regular expression to check if a string contains at least one special character.  
Input: containsSpecialCharacter("Hello@World")  
Expected Output:  
True

Q20: Write a regular expression to remove all digits from a string.  
Input: removeDigits("PHP123Programming")  
Expected Output:  
PHPProgramming

Q21: Write a regular expression to find duplicate words in a string.  
Input: findDuplicates("This is is a test test")  
Expected Output:  
["is", "test"]

Q22: Write a regular expression to check if a string contains a valid URL.  
Input: isValidURL("https://example.com")  
Expected Output:  
True

Q23: Write a regular expression to replace multiple spaces in a string with a single space.  
Input: replaceMultipleSpaces("This   is   PHP")  
Expected Output:  
This is PHP

Q24: Write a regular expression to validate a 5-digit ZIP code.  
Input: validateZip("12345")  
Expected Output:  
True

Q25: Write a regular expression to check if a string contains both uppercase and lowercase letters.  
Input: containsBothCases("Hello")  
Expected Output:  
True

Q26: Write a regular expression to remove all vowels from a string.  
Input: removeVowels("Hello World")  
Expected Output:  
Hll Wrld

Q27: Write a regular expression to validate a time in the format HH:MM (24-hour format).  
Input: validateTime("14:30")  
Expected Output:  
True

Q28: Write a regular expression to find all numeric values in a string.  
Input: findNumbers("The price is 45 and 100.")  
Expected Output:  
[45, 100]

Q29: Write a regular expression to check if a string starts with a specific letter (e.g., 'A').  
Input: startsWithA("Apple")  
Expected Output:  
True

Q30: Write a regular expression to validate a credit card number (16 digits).  
Input: validateCard("1234567812345678")  
Expected Output:  
True

Q31: Write a regular expression to replace all lowercase letters in a string with uppercase letters.  
Input: replaceWithUppercase("hello world")  
Expected Output:  
HELLO WORLD

Q32: Write a regular expression to extract the domain name from an email address.  
Input: extractDomain("user@example.com")  
Expected Output:  
example.com

Q33: Write a regular expression to check if a string contains a valid hashtag (e.g., #example).  
Input: isValidHashtag("#LearnPHP")  
Expected Output:  
True

Q34: Write a regular expression to check if a string contains only alphanumeric characters.  
Input: isAlphanumeric("Hello123")  
Expected Output:  
True

Q35: Write a regular expression to count the number of words starting with 'P' in a string.  
Input: countWordsStartingWithP("PHP Programming is Powerful")  
Expected Output:  
3

Q36: Write a regular expression to extract all email addresses from a string.  
Input: extractEmails("Contact us at support@example.com or sales@example.org")  
Expected Output:  
["support@example.com", "sales@example.org"]

Q37: Write a regular expression to validate a username (only letters, digits, and underscores, 3-15 characters).  
Input: validateUsername("user_123")  
Expected Output:  
True

Q38: Write a regular expression to check if a string contains repeating characters.  
Input: hasRepeatingCharacters("book")  
Expected Output:  
True

Q39: Write a regular expression to replace all HTML tags in a string with an empty string.  
Input: removeHTMLTags("<h1>Welcome</h1> to <b>PHP</b>")  
Expected Output:  
Welcome to PHP

Q40: Write a regular expression to validate a MAC address (e.g., 00:1A:2B:3C:4D:5E).  
Input: validateMAC("00:1A:2B:3C:4D:5E")  
Expected Output:  
True

Q41: Write a regular expression to check if a string is a valid binary number (only 0s and 1s).  
Input: isBinary("101010")  
Expected Output:  
True

Q42: Write a regular expression to extract all uppercase words from a string.  
Input: extractUppercaseWords("THIS is A TEST")  
Expected Output:  
["THIS", "A", "TEST"]

Q43: Write a regular expression to check if a string contains a valid file path (e.g., C:\Program Files).  
Input: validateFilePath("C:\\Program Files")  
Expected Output:  
True

Q44: Write a regular expression to find all substrings enclosed in double quotes.  
Input: findQuotedStrings('He said "Hello" and "Goodbye".')  
Expected Output:  
["Hello", "Goodbye"]

Q45: Write a regular expression to remove all non-alphanumeric characters from a string.  
Input: removeNonAlphanumeric("Hello @World!123")  
Expected Output:  
HelloWorld123

Q46: Write a regular expression to validate a hexadecimal number (e.g., 0x1A3F).  
Input: validateHexNumber("0x1A3F")  
Expected Output:  
True

Q47: Write a regular expression to check if a string contains consecutive repeated characters.  
Input: hasConsecutiveRepeats("balloon")  
Expected Output:  
True

Q48: Write a regular expression to replace all digits in a string with '#'.  
Input: replaceDigits("Phone: 123-456-7890")  
Expected Output:  
Phone: ###-###-####

Q49: Write a regular expression to extract the file extension from a filename.  
Input: getFileExtension("document.pdf")  
Expected Output:  
pdf

Q50: Write a regular expression to validate a US Social Security Number (format: 123-45-6789).  
Input: validateSSN("123-45-6789")  
Expected Output:  
True