GoLand 2019.3 Help

How to search and replace with regular expressions

When you want to search and replace specific patterns of text, use regular expressions. They can help you in pattern matching, parsing, filtering of results, and so on. Once you learn the regex syntax, you can use it for almost any language.

  1. Press Ctrl+R to open the search and replace pane.

  2. Enter a search string in the top field and a replace string in the bottom field.

    Regex search and replace fields

    By default, the Regex checkbox is selected. If you need to check the regex syntax reference, click the question mark next to Regex.

  3. When you search for a text string that contains special regex symbols, GoLand automatically escapes them with backlash \ in the search field.

    Escape regex symbols

    However, when you specifically search for metacharacters such as .[{()\^$|?*+, you need to escape them with backslash \, so they can be recognized.

    For example, if you need to find ., type \. in the search field.

  4. GoLand can also match a letter case when you enter a range of characters in your search field.

    For example, if you want to search for only uppercase characters, type the following in the search field:

    \b[A-Z]

    To search and replace more complicated patterns, use the structural search and replace.

  5. If the Match Case checkbox is cleared, GoLand searches for both lower and upper cases. Select the Match Case checkbox to match the case of the specified range.

    The result of the Match Case selection

  6. When you browse the occurrences, GoLand displays the replacement hints, so you can view the potential results before clicking the Replace button.

    Replacement hints

Use regex capturing groups and backreferences

You can put the regular expressions inside brackets in order to group them. Each group has a number starting with 1, so you can refer to (backreference) them in your replace pattern. Note that the group 0 refers to the entire regular expression.

Let's consider the following code:

<new product="ij" category="105" title="Multiline search and replace in the current file"/> <new product="ij" category="105" title="Improved search and replace in the current file"/> <new product="ij" category="105" title="Regexp shows replacement preview"/>
  1. Open the search and replace pane Ctrl+R.

  2. In the search field, enter parentheses () that would indicate a capturing group, for example: \stitle="(.*)?"\s*(/>*)

  3. In the replace field, backreference such groups by numbers starting with 1, for example:

    $2<title>$1</title>

  4. GoLand highlights the found occurrences based on your search specifications and displays hints with the replace string.

    Replace with regex result

Switch the character case

You can use regular expressions to change the case of characters that matches some criteria.

  1. Open the search and replace pane Ctrl+R. Make sure that the Regex checkbox is selected.

  2. In the search field enter the search pattern.

  3. In the replace field, depending on what you want to achieve, enter one of the following syntax:

    • \l changes a character to lowercase until the next character in the string.
      For example, Bar becomes bar.

    • \u changes a character to uppercase until the next character in the string.
      For example, bar becomes Bar.

    • \L changes characters to lowercase until the end of the literal string \E.
      For example, BAR becomes bar.

    • \U changes characters to uppercase until the end of the literal string \E.
      For example, bar becomes BAR.

    Switch to the uppercase character example

The following XML code fragment is used as an example for this tutorial.

<new product="ij" category="105" title="Multiline search and replace in the current file" /> <new product="ij" category="105" title="Improved search and replace in the current file" /> <new product="ij" category="105" title="Regexp shows replacement preview" /> ...
Last modified: 5 December 2019