How to check if String starts with a Prefix in Go?

Go – Check if String starts with Prefix

To check if a string starts with a given prefix string in Go language, call HasPrefix function of strings package, and pass the string and prefix string as arguments to it.

The syntax to check if string str starts with prefix string prefix using HasPrefix function is

strings.HasPrefix(str, prefix)

HasPrefix function returns a boolean value. It returns true if string str starts with string prefix.

Examples

In the following example, we take two strings, str and prefix, and check if str starts with prefix using HasPrefix function.

example.go

package main

import (
	"fmt"
	"strings"
)

func main() {
	str := "Hello World!"
	prefix := "Hello"
	if strings.HasPrefix(str, prefix) {
		fmt.Println("The string starts with given prefix.")
	} else {
		fmt.Println("The string does not start with given prefix.")
	}
}

Output

The string starts with given prefix.

Conclusion

In this Golang Tutorial, we learned how to check if a string starts with a given prefix string in Go programming language, with the help of example programs.