Question

Do you know a java method to expand the chars of a text into spaces?

My text:

1. <tab>  firstpoint  <tab> page  1
10. <tab> secondpoint <tab> page 10

If I directly replace the tab by, let say, 4 spaces, I will have

1.    firstpoint    page1
10.    secondpoint    page2

Instead of it, I need a method to replace each tab by the number of spaces it really corresponds to (as the command :retab of vim does). Any solution?

Answer 1

Although there’s probably a library out there that does this, the manual solution is quite simple:

1. Create an output buffer (StringBuilder).
2. Iterate through the string’s characters
3. For each character check if it’s a tab or not.
   a. If it’s not a tab, add it to the output buffer.
   b. If it’s a tab, add a space first, then as many spaces as it takes for the length of the output buffer to be divisible by 4. (Your tab length.)
4. Return the output buffer.