如何检查Go中字符串的第一个字符，即使它是空白的？

Question

I want to have the user be able to put in input and check to see if the first character is an "a" but if they leave the string empty then it will cause an error that outputs

panic: runtime error: index out of range [0] with length 0

My code looks like

package main
import "fmt"
func main() {
        var a string;
        fmt.Scanln(&a);
        if string(a[0]) == "a" {
                fmt.Println("if true");
        } 
}

Answer 1

One way to do it, will only check if the first character is "a"

if len(a) > 0 && string(a[0]) == "a" {
    fmt.Println("if true")
}

Another, will work with leading spaces, for example " a"

if strings.HasPrefix(a, “a”) {
    fmt.Println("if true")
}