Regex Matching in golang - go

Question

How do you match the string ello w in hello world
Got to this error from trying this example
package main
import (
"fmt"
"regexp"
)
func check(result string ) string {
if (regexp.MatchString("b\\ello w\\b",result)) {
fmt.Println("Found it ")
return "True"
} else {
return "False"
}
}
func main() {
text := "Hello world "
check (text)
}
throws the following error
# command-line-arguments
.\test.go:14:5: multiple-value regexp.MatchString() in single-value context

Answer 1

regexp.MatchString returns two value. When you use it in your if conditional, compiler fails.
You should assign the return values first, then handle error case and then the match case
By the way your regex was also faulty, please see the code for a correct one for your case
https://play.golang.org/p/dNEsa9mIfhE
func check(result string ) string {
// faulty regex
// m, err := regexp.MatchString("b\\ello w\\b",result)
m, err := regexp.MatchString("ello w",result)
if err != nil {
fmt.Println("your regex is faulty")
// you should log it or throw an error
return err.Error()
}
if (m) {
fmt.Println("Found it ")
return "True"
} else {
return "False"
}
}
func main() {
text := "Hello world "
check(text)
}

Answer 2

MatchString() returns 2 values, a bool and an error, so your if statement doesn't know how to process that. https://pkg.go.dev/regexp#MatchString
In the correction below, I just through away the error value but I would recommend actually checking and handling the error.
https://play.golang.org/p/awAFxxAMyWl
package main
import (
"fmt"
"regexp"
)
func check(result string ) string {
found, _:= regexp.MatchString(`ello w`,result)
if (found) {
fmt.Println("Found it ")
return "True"
} else {
return "False"
}
}
func main() {
text := "Hello world "
fmt.Println(check(text))
}