Add: StringUtils.Substring

This commit is contained in:
dennis 2023-10-30 11:38:38 +08:00
parent b7801dc550
commit 2d07e6c6ee
2 changed files with 84 additions and 0 deletions

View File

@ -33,3 +33,36 @@ func (s *StringUtils) LeftPad(str string, size int, padStr string) string {
return strings.Repeat(padStr, padCount) + str return strings.Repeat(padStr, padCount) + str
} }
func (s *StringUtils) Substring(str string, start, end int) string {
if str == "" {
return str
}
runes := []rune(str)
if end < 0 {
end = len(runes) + end
}
if start < 0 {
start = len(runes) + start
}
if end > len(str) {
end = len(str)
}
if start > end {
return EMPTY
}
if start < 0 {
start = 0
}
if end < 0 {
end = 0
}
return string(runes[start:end])
}

51
StringUtils_test.go Normal file
View File

@ -0,0 +1,51 @@
package golanghelper_test
import (
"testing"
"gitlab-ce.niaulang.com/niau-lang/golanghelper"
)
func TestSubstring(t *testing.T) {
stringUtils := golanghelper.StringUtils{}
s := stringUtils.Substring("", 0, 0)
if s != "" {
t.Errorf("預期的值為空字串, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", 0, 2)
if s != "ab" {
t.Errorf("預期的值為 ab, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", 2, 0)
if s != "" {
t.Errorf("預期的值為空字串, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", 2, 4)
if s != "c" {
t.Errorf("預期的值為 c, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", 4, 6)
if s != "" {
t.Errorf("預期的值為空字串, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", 2, 2)
if s != "" {
t.Errorf("預期的值為 ab, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", -2, -1)
if s != "b" {
t.Errorf("預期的值為 b, 卻回傳 %v", s)
}
s = stringUtils.Substring("abc", -4, 2)
if s != "ab" {
t.Errorf("預期的值為 ab, 卻回傳 %v", s)
}
}