added function DefaultString, DefaultIfBlank

stringutils.go

@@ -222,3 +222,19 @@ func IndexOf(str string, sub string, start int) int {
 func IsEmpty(str string) bool {
 	return len(str) == 0
 }
+
+// Returns either the passed in string, or if the string is empty, the value of defaultStr.
+func DefaultString(str string, defaultStr string) string {
+	if IsEmpty(str) {
+		return defaultStr
+	}
+	return str
+}
+
+// Returns either the passed in string, or if the string is whitespace, empty (""), the value of defaultStr.
+func DefaultIfBlank(str string, defaultStr string) string {
+	if IsBlank(str) {
+		return defaultStr
+	}
+	return str
+}

stringutils_test.go

@@ -307,3 +307,33 @@ func ExampleIndexOfDifference() {
 	// 0
 	// 2
 }
+
+func ExampleDefaultString() {
+
+	out1 := DefaultString("abc", "")
+	out2 := DefaultString("ab", "c")
+	out3 := DefaultString("", "abc")
+
+	fmt.Println(out1)
+	fmt.Println(out2)
+	fmt.Println(out3)
+	// Output:
+	// abc
+	// ab
+	// abc
+}
+
+func ExampleDefaultIfBlank() {
+
+	out1 := DefaultIfBlank("", "abc")
+	out2 := DefaultIfBlank(" ", "abc")
+	out3 := DefaultIfBlank("ab", "cd")
+
+	fmt.Println(out1)
+	fmt.Println(out2)
+	fmt.Println(out3)
+	// Output:
+	// abc
+	// abc
+	// ab
+}