Use the pattern /^([ \t]+)/gm with the String.match() or String.matchAll() method. For example: const matches = text.match(/^([ \t]+)/gm);

Question 1

What does the Line Indentation regex pattern do?

Accepted Answer

Captures leading spaces and tabs at the start of each line. Group 1 contains the indentation string for measuring indent level.

Question 2

How do I use the Line Indentation regex in JavaScript?

Accepted Answer

Use the pattern /^([ 	]+)/gm with the String.match() or String.matchAll() method. For example: const matches = text.match(/^([ 	]+)/gm);

Question 3

What regex flags does this pattern use?

Accepted Answer

This pattern uses the global, multiline flags (gm). The global flag finds all matches in the input, not just the first.

Question 4

Which programming languages support this regex?

Accepted Answer

Fully supported in JS, PYTHON, JAVA, PHP, GO

Question 5

What strings does this regex match?

Accepted Answer

This pattern matches strings like:   two spaces, 	one tab,     four spaces. It does not match strings like: no indent, .

Line Indentation

Pattern