# Using Regular Expression to search in text editor

HackMD supports regular expression, or regex in short, which is a powerful tool to find strings that match certain pattern in the note. Please use [Javascript's regex syntax](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions).

### Steps:
1. When in Sublime Editor mode, hit `ctrl + f` (or `cmd + f` if on Mac) to show the search bar at the top of the editing area.
2. Type `/<regular expression>/` in the search bar, replace the `<regular expression>` with your regular expression. **REMEMBER** to keep the slashes, otherwise it would be just a normal search.
3. See matched words in the editor highlighted in yellow (Note, the highlight does not show in the preview area.

# **Example**

Type `/ei./` in the search bar would highlight "being", "sein", "heidegger", and "dasein" in the following example text.


### Example Text:
Being and Time (German: Sein und Zeit) is a 1927 book by the German philosopher Martin Heidegger, in which the author seeks to analyse the concept of Being. Heidegger maintains that this has fundamental importance for philosophy and that, since the time of the Ancient Greeks, philosophy has avoided the question, turning instead to the analysis of particular beings. Heidegger attempts to revive ontology through a reawakening of the question of the meaning of being. He approaches this through a fundamental ontology that is a preliminary analysis of the being of the being to whom the question of being is important, i.e., Dasein, or the human being in the abstract.