Hey , how to delete everything from the double slash until the end of the line in java? In addition these groups also create a back reference to the part of the regular expression. A back reference stores the part of the String which matched the group. A makes the This Java regex tutorial will explain how to use this API to match regular expressions against text. If you want to test these examples, create for * replaceAll(). Let’s, for example, assume you want to replace all whitespace between a letter followed by a point or a comma. Instantly share code, notes, and snippets. // Pattern pattern = Pattern.compile("\\s+", Pattern.CASE_INSENSITIVE); // now create a new pattern and matcher to replace whitespace with tabs, , Now offering virtual, onsite and online training, 3.6. // Removes whitespace between a word character and . If you want to define \w, then you must be using \\w in your regex. These methods are not optimized for performance. Which means that to use it as a normal backslash character, you need to escape it twice. A whitespace character, short for [ \t\n\x0b\r\f], Matches a word boundary where a word character is [a-zA-Z0-9_]. Occurs zero or more times, is short for {0,}, X* finds no or several letter X, . Create for the following example the Java project Specifying modes inside the regular expression, 4. number. You can group parts of your regular expression. If you want to replace a single backslash in Java using replaceAll there are multiple layers of escaping that leads to four backslashes as an argument for replaceAll.. to search across multiple lines. Occurs X number of times, {} describes the order of the preceding liberal. statements. The following screenshots demonstrate how to search for the