Find all string matches with Regex golang

Question

I am trying to return an array, or slice, with all the matches for a specific regex expression against a string. The string is:

{city}, {state} {zip}

I want to return an array with all the matches of strings between curly braces. I have tried using the regexp package to accomplish this but cannot figure out how to return what I am looking for. This is my current code:

r := regexp.MustCompile("/({[^}]*})/")
matches := r.FindAllString("{city}, {state} {zip}", -1)

But, all it returns is an empty slice every time no matter what I try.

Solution

First, you do not need the regex delimiters. Second, it is a good idea to use raw string literals to define a regex pattern where you need to use only 1 backslash to escape regex metacharacters. Third, the capturing group is only necessary if you need to get the values without { and }, thus, you may remove it to get {city}, {state} and {zip}.

You may use FindAllString to get all matches:

r := regexp.MustCompile(`{[^{}]*}`)
matches := r.FindAllString("{city}, {state} {zip}", -1)

See the Go demo.

To only get the parts between curly braces use FindAllStringSubmatch with a pattern that contains capturing parentheses, {([^{}]*)}:

r := regexp.MustCompile(`{([^{}]*)}`)
matches := r.FindAllStringSubmatch("{city}, {state} {zip}", -1)
for _, v := range matches {
    fmt.Println(v[1])
}

See this Go demo.

Regex details

• { - a literal { char
• ([^{}]*)- a capturing group that matches any 0 or more (due to the * quantifier) characters other than { and } ([^...] is a negated character class matching any char but the one(s) specified between [^ and ])
• } - a literal } char