wkaczurba

Regex

Changing multiple spaces in Java into single ones

Java - + vs *

This is where + and * characters matters:

• replaceAll("[ ]+", " ")

This will mess things up:

• replaceAll("[ ]*", " ")

Sed -e vs -E

This does not work (-e) -> it is to add scripts one after another

• echo "This is some input HAHA" | sed -e 's/[ \t]+/ /g'

This works though (-E) -> thi is for -E, -r, –regexp-extended

• echo "This is some input HAHA" | sed -e 's/[ \t]+/ /g'

With -E the following will work:

• echo "Abbbba" | sed -E 's/[b]{2}//' and will produce Abba (changing exactly bb into ``)