How do you replace a line in Notepad++?

To replace a line or specific text within a line in Notepad++, you primarily use the powerful Find and Replace feature. This tool allows you to quickly locate and modify text throughout your document, including inserting new lines or completely altering existing ones.

Understanding Find and Replace in Notepad++

The Find and Replace dialog is your main interface for making text substitutions. It can handle simple text strings or complex patterns using regular expressions, offering flexibility for various replacement needs.

How to Access Find and Replace

1. Open Notepad++.
2. Go to Search > Replace... (or press Ctrl + H).

The Replace dialog box will appear, offering several options:

Field	Description
Find what:	Enter the text or pattern you want to locate.
Replace with:	Enter the text or pattern you want to use as a substitute. This is where you can insert special characters like \r for a carriage return.
Search Mode:	Choose how Notepad++ should interpret your Find what and Replace with inputs: Normal: Simple text matching. Extended: Allows use of special characters like \t (tab), \n (line feed), \r (carriage return). Regular expression: For advanced pattern matching.

Replacing Specific Text Within a Line

The most common use is to replace a specific string wherever it appears within your document, which naturally includes parts of lines.

Example: Replacing a word

Suppose you have lines like:
This is line one.
This is line two.

And you want to change "is" to "was".

1. Open the Replace dialog (Ctrl + H).
2. In Find what:, type is.
3. In Replace with:, type was.
4. Select Search Mode: Normal.
5. Click Replace All to change all occurrences, or Replace to change one at a time.

Result:
This was line one.
This was line two.

Inserting a New Line (Carriage Return) by Replacing a Pattern

You can effectively "replace a line" by modifying its structure through the insertion of new line characters. Notepad++ allows you to use \r for a carriage return and \n for a line feed within the "Replace with" field, particularly useful when Search Mode is set to Extended or Regular expression.

Practical Insight: If you need to break up a long line or a series of text strings into separate lines based on a delimiter, you can replace that delimiter with a new line character.

Example: Replacing "comma and space" with a new line

If you have a line of text where items are separated by a comma and a space, like:
Item1, Item2, Item3, Item4

And you want each item on a new line:
Item1
Item2
Item3
Item4

1. Open the Replace dialog (Ctrl + H).
2. In Find what:, type ,.
3. In Replace with:, type \r (or \n or \r\n depending on your desired line ending format for Windows/Unix).
4. Select Search Mode: Extended.
5. Click Replace All.

Result:
Item1
Item2
Item3
Item4

Here, \r is interpreted as a carriage return, which moves the cursor to the beginning of the current line, effectively starting a new line in combination with \n (line feed) in most Windows environments. Using \r\n is often the most reliable way to create a standard Windows new line.

Replacing an Entire Line Using Regular Expressions

To replace the entire content of one or more lines, you'll need to use Search Mode: Regular expression to match the full line and its line ending.

Example: Replacing a specific line's content

Let's say you have:
Line A: This is some content.
Line B: This is the line to be replaced.
Line C: More content here.

And you want to replace "Line B: This is the line to be replaced." with "Line B: New updated content."

1. Open the Replace dialog (Ctrl + H).
2. In Find what:, type ^Line B: This is the line to be replaced.\R.
   • ^ matches the beginning of a line.
   • .* matches any character (except newline) zero or more times.
   • \R matches any kind of line break sequence (CR, LF, CRLF). This is crucial to ensure the line ending is also included and replaced, preventing lines from merging.
3. In Replace with:, type Line B: New updated content.\R.
4. Select Search Mode: Regular expression.
5. Click Replace All (or Replace if you want to be selective).

Result:
Line A: This is some content.
Line B: New updated content.
Line C: More content here.

Understanding Regex for Line Replacement:

• ^: Matches the beginning of a line.
• $: Matches the end of a line (before the line ending characters).
• .*: Matches any character (except newline) zero or more times.
• \R: Matches any Unicode line break sequence (e.g., \n, \r, \r\n). This is generally preferred over \n or \r\n because it adapts to different file formats.

By mastering the Find and Replace feature with regular expressions and special characters like \r for carriage returns, you can efficiently manipulate and replace lines of text in Notepad++.