How to validate IP address using regular expression? The reason is two “second” words have the first character in capital letters. Method to check if a String contains a sub string ignoring case in Java; Check if a string contains only alphabets in Java using Regex; How do we check if a String contains a substring (ignoring case) in Java? In a Java program, you want to determine whether a String contains a case-insensitive regular expression (regex). Here is the detail of parameters − str − the String to be compared. Simple java regex using Pattern and Matcher classes. Java Regular Expression : Split text: 14. List Of Regular Expression Sample Programs: Simple regex pattern matching using string matches(). Get all digits from a string: 16. In Java, by default, the regular expression (regex) matching is case sensitive. You don't want to manipulate the String or extract the match, you just want to determine whether the pattern exists at least one time in the given String. The string against which we evaluated our expression has a “second” word 3 times, but the pattern only matched once. How to extract a group from a Java String that contains a Regex pattern; How to test if a string contains specific words in Java? Return Value. It's mid-way between the using a regular expression and using toLowerCase on the entire search string: the search string needs to be over about 60 characters before the regular expression was faster. To enable the regex case insensitive matching, add (?) Two characters c1 and c2 are considered the same ignoring case if … Java Regular Expression :split 2: 15. Problem: In a Java program, you want to determine whether a String contains a pattern, you want your search to be case-insensitive, and you want to use String matches method than use the Pattern and Matcher classes.. How to replace a pattern using regular expression in java? Strip extra spaces in a XML string: 17. Split a String into a Java Array of Strings divided by an Regular Expressions: 12. Two strings are considered equal ignoring case, if they are of the same length, and corresponding characters in the two strings are equal ignoring case. Regular Expression Replace: 13. The contains() method of the String class accepts Sting value as a parameter, verifies whether the current String object contains the specified String and returns true if it does (else false).. Case Insensitive Matching. Solution: Use the String matches method, and include the magic (?i:X) syntax to make your search case-insensitive. String matches() perform case sensitive matching. int compareToIgnoreCase(String str) Parameters. If you want case insensitive matching, there are two options. Java regex with case insensitive. Remove trailing white space from a string: 18. Syntax. Compares this String to another String, ignoring case considerations. Two strings are considered equal ignoring case if they are of the same length and corresponding characters in the two strings are equal ignoring case. Since the Java regular expressions are case sensitive by default they did not match with our pattern which has all the lower case letters.. 4. Use Pattern class directly and compile it with Pattern.CASE_INSENSITIVE flag. Here is the syntax of this method − public boolean equalsIgnoreCase(String anotherString) Parameters. The toLoweCase() method of the String class converts all the characters in the current String into lower case and returns.. To find whether a String contains a particular sub string irrespective of case − prefix or enable the case insensitive flag directly in the Pattern.compile().. A regex pattern example. This method returns a negative integer, zero, or a positive integer as the specified String is greater than, equal to, or less than this String, ignoring case considerations. Java String FAQ: How can I tell if a Java String contains a given regular expression (regex) pattern? The problem with that though is that there is no "NoCase" type methods built into the Java string (except for String::equalsIgnoreCase(), but that doesn't use regular expressions). Example