Golang : Count number of runes in string
This just a note for myself and perhaps it can be useful to you as well.
To count a length(size) of a string, typically a programmer will just settle for the the builtin.Len() function. However, when dealing with strings with utf8 characters. Please use the utf8.RuneCountInString() function. See the code below to know why :
package main
import (
"fmt"
"unicode/utf8"
)
func main() {
str := "abc"
fmt.Printf("Length %s with len() is %d\n", str, len(str)) // correct
unicodeStr := "fuß"
fmt.Printf("Length %s with len() is %d\n", unicodeStr, len(unicodeStr)) // incorrect
fmt.Printf("Length %s with utf8.RuneCountInString() is %d\n", unicodeStr, utf8.RuneCountInString(unicodeStr)) // correct
unicodeStr2 := "你好"
fmt.Printf("Length %s with len() is %d\n", unicodeStr2, len(unicodeStr2)) // incorrect
fmt.Printf("Length %s with utf8.RuneCountInString() is %d\n", unicodeStr2, utf8.RuneCountInString(unicodeStr2)) // correct
}
Output :
Length abc with len() is 3
Length fuß with len() is 4
Length fuß with utf8.RuneCountInString() is 3
Length 你好 with len() is 6
Length 你好 with utf8.RuneCountInString() is 2
See also : Golang : convert rune to integer value
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
+14.8k Golang : Delete files by extension
+4.3k Javascript : Change page title to get viewer attention
+10.1k Google Maps URL parameters configuration
+3.8k Golang : Experimental Jawi programming language
+7k Golang : Append and add item in slice
+6.6k Golang : Generate human readable password
+7.7k Golang : Random integer with rand.Seed() within a given range
+14.2k Golang : Intercept Ctrl-C interrupt or kill signal and determine the signal type
+6k Linux : How to fix Brother HL-1110 printing blank page problem
+6.4k Golang : Hue, Saturation and Value(HSV) with OpenCV example
+8.5k Golang : Format strings to SEO friendly URL example