Golang : cannot assign type int to value (type uint8) in range error
Sometimes, we tend to overlook a small part of for--loop just because we use it frequently and expect the compiler or linker to alert us of the problem before run time. The problem described below is only visible during run time :
Problem :
You get an error message that look like this :
cannot assign type int to value (type uint8) in range
or something similar when trying to use range. For example :
package main
import "fmt"
func main() {
var xs []uint8 = []uint8{123, 124, 125}
var value uint8
for value = range xs {
fmt.Println(value)
}
}
Solution :
That is because, range over a slice or array will return 2 values.... but yet the code will compile will issue! To fix this error. Change the codes to :
package main
import "fmt"
func main() {
var xs []uint8 = []uint8{123, 124, 125}
var value uint8
for _, value = range xs { // ignore the key
fmt.Println(value)
}
}
or
package main
import "fmt"
func main() {
var xs []uint8 = []uint8{123, 124, 125}
var key uint8
var value uint8
for key, value = range xs { // assign the key to a variable.
fmt.Println(key, value)
}
}
output :
0 123
1 124
2 125
By Adam Ng
IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.
Advertisement
Tutorials
+12.8k Golang : Get uploaded file name or access uploaded files
+8.6k Javascript : Read/parse JSON data from HTTP response
+8.5k Golang : Resumable upload to Google Drive(RESTful) example
+19.5k Golang : Create and resolve(read) symbolic links
+11.3k Golang : Get absolute path to binary for os.Exec function with exec.LookPath
+4.4k Javascript : How to loop over and parse JSON data?
+5.9k Golang : How to call function inside template with template.FuncMap
+5k Golang : Dealing with backquote
+12k Golang : Date and Time formatting
+11.7k Golang : Increment string example
+5.5k Golang : When to use make or new?