Preface

because golang Regular matching rules such as pre check are not supported ,regex The package does not support ?= And so on , Complex regular matching is difficult to achieve , Open source packages are available regex2

One 、 Installation package go get github.com/dlclark/regexp2

Two 、 Use

The code is as follows （ Example ）：

func matchStr(str string) string {
    
	expr := `^(?![0-9a-zA-Z]+$)(?![a-zA-Z!@#$%^&*]+$)(?![0-9!@#$%^&*]+$)[0-9A-Za-z!@#$%^&*]{8,16}$`
	reg, _ := regexp2.Compile(expr, 0)
	m, _ := reg.FindStringMatch(str)
	if m != nil {
    
		res:= m.String()
		return res
	}
	return " The password contains at least one digit , Letters and special characters , And length 8-16"
}

3、 ... and 、 explain

(?![0-9a-zA-Z]+$) Indicates a match followed by a non number , Non alphabetic characters

(?![a-zA-Z!@#$%^&*]+$) Indicates a match followed by a non letter , Non special characters

(?![0-9!@#$%^&*]+$) Indicates a match followed by a non number , Non special characters

[0-9A-Za-z!@#$%^&*]{8,16} Length 8-16, It can be any number , Letters and the special characters they contain