Simple Groovy replace using regex

Question

I've been reading through regex and I thought this would work but it doesn't seem to want to work. All I need to do is strip the leading 1 off a phone number if it exists.

So:

def mphone = 1+555-555-5555
mphone.replace(/^1/, "")

Shouldn't this output [phone]?

Solution 1

I recognize two errors in your code. First one is probably a typo: you are not surrounding the phone number with quotation marks so it's an integer: 1 + 555 - 555 - 5555 = -5554

Also, you should use replaceFirst since there's no method replace in String taking a Pattern as first parameter. This works:

def mphone = "1+555-555-5555"
result = mphone.replaceFirst(/^1/, "")

Solution 2

replace is a java Method of Java's String, which replace a character with another:

assert "1+555-551-5551".replace('1', ' ') == " [phone] "

What you are looking for is replaceAll, which would replace all occurrences of a regex, or replaceFirst, that would replace the first occurrence only:

assert "1+555-551-5551".replaceAll(/1/, "") == "[phone]"
assert "1+555-551-5551".replaceFirst(/1/, "") == "[phone]"

The ^ in your regex means that the one must be at the beginning:

assert "1+555-551-5551".replaceAll(/^1/, "") == "[phone]"

so the code you posted was almost correct.

Comments

[Antoine]

You meant def mphone = "1+555-555-5555" (with quotes)

[Johnathon Sanders]

Good answer. One caveat, don't forget Strings are immutable. Make sure to reassign mphone: mphone = mphone.replaceFirst(/^1/, "")

[Esteban]

@Johnathon great comment, using the last line as a return value would do but I didn't think it could also be a mistaken in-place replacement

[Ashok Koyi]

String contains replace(CharSequence, CharSequence) method