How to add a space or a string into the substitute expression?

Question

I am trying Vim capabilities and stuck with this task - addition the incrementing number to the end of each line.

Testing lines:

text
text
text
text
text

This command works partially:

:let n=1 | g/text/s/$/\=n/ | let n+=1

Result:

text1 
text2 
text3 
text4 
text5 

But I want to have space between the added numbers and the 'text'.

The adding of space ' ' before the \=doesn't work, because the \= should be in the beginning of substitute expression, else it is not parsed as an expression, but inserted literally - text =n:

:let n=1 | g/text/s/$/ \=n/ | let n+=1 ### doesn't work as expected

So, the questions:

1. Is it possible to insert a string in the substitute expression?

Like this (the n is the variable):

s/$/string\=n/
s/$/'string'\=n/

or this:

s/$/\='string'n/

2. Can I use multiple variables in the substitute expression by separating them from each other like in the bash?

Example:

s/$/\={var_1}{var_2}{var_3}/

3. Do you know more suitable/simple way for solving this task?

Answer 1

For your answer specifically, you could get around this by concatenating a space with the number, i.e.

:let n=1 | g/text/s/$/\=" ".n/ | let n+=1

---

If you want to do this to every line, there are some much shorter ways to do this. For example:

:%s/$/\=" ".line('.')

Or if you only want to number the lines matching "text", then either of these:

:%s/text/\=submatch(0)." ".line('.')
:%s/text\zs/\=" ".line('.')

You could even do the entire thing in normal mode. For example, you could do this:

gg<C-v>G$A 0<esc>gvg<C-a>

Where <C-v> means ctrl-v and <C-a> means ctrl-a

Answer 2

Answer to the question №1:

:let n=1 | g/text/s/$/\=printf(" %d", n)/ | let n+=1

Result

text 1 
text 2 
text 3 
text 4 
text 5 

Answer to the question №2:

The substitute expression can contain multiple variables separated (concatenated) by dot . operator.

:let a = 'one'
:let b = 'two'
:let c = 'three'
:g/text/s/$/\=a.b.c/

Result

textonetwothree 
textonetwothree 
textonetwothree 
textonetwothree 
textonetwothree

If it is needed separate them by space, then do:

:g/text/s/$/\=' '.a.' '.b.' '.c/

or

:g/text/s/$/\=printf(' %s %s %s', a, b, c)/

Result

text one two three 
text one two three 
text one two three 
text one two three 
text one two three