How to replace a string at specific line number in a text file?

%%.text file contain%%%

In this

part a

simple

method for

floating‐point

to fixed‐point

%%%new .text file contain%%

In this

part a

simple

method for

/////newly added string///

to fixed‐point

how to replace the string at specific line number?

[Guillaume]

line 4 and 5 of what? A text file? A char vector (with some line returns), a scalar string (with some line returns)?

[raju patel]

I have updated the question.sorry for that.

[Rik]

Adding the names of frequent contributors as tags only proves you have seen several questions, which means you should know how to write a complete question. It generally does not attract actual attention.

Answer 1

[Andrew Janke]

Try this:

• Read in the whole text file
• Split it on \r?\n to break it in to lines
• Now you have an array of lines, so you can edit line(i) to modify just the i-th line
• Use strrep or regexprep to modify the contents of that line
• Use strjoin() to join all the lines back together into a single string
• Write that string out to your new file