For example, it is now necessary to determine whether the command line has passed parameters, that is, whether [1] exists
If the following judgment is used:
package main
import (
"fmt"
"os"
)
func main() {
if [1] != "" {
("aaa")
} else {
("bbb")
}
}
An error will be reported: index out of range
panic: runtime error: index out of range goroutine 1 [running]: () /root/workspace/go/:9 +0x100 exit status 2
Correct way to deal with it:
Through traversal, determine whether key = 1 exists
package main
import (
"fmt"
"os"
)
func main() {
var target string // Used to obtain the final required [1] for k, v := range() {
if k == 1 { // Assume that you need to obtain [k], k = 1 target = v
}
}
if target != "" { // Not empty means [1] exists ("[1] = %s", target)
}
}
Supplement: Regular match in golang & determine whether the element is in slice or array
1. Regular matching
package main
import (
"fmt"
"regexp"
)
func main() {
//pattern := "\\d+" //Backslashes need to be escaped pattern := "[a-zA-Z]" //Match letters str := "a1.22.35.4"
result, _ := (pattern, str)
(result) //true
}
2. Determine whether the element is in a slice or an array
package main
import "fmt"
import "/wxnacy/wgo/arrays"
//go get /wxnacy/wgo/arrays installation package
func main() {
str := "342"
var numbers []string
numbers = append(numbers, "3332", "342", "ssddd", "ssss", "%%%%")
index := (numbers, str)
if index == -1 {
("not exists") //-1 means that it does not exist } else {
(index) //If it exists, it will return the subscript of the element }
}
The above is personal experience. I hope you can give you a reference and I hope you can support me more. If there are any mistakes or no complete considerations, I would like to give you advice.