Created

randx/rand.go

@@ -0,0 +1,46 @@
+package randx
+
+import (
+	"crypto/rand"
+	"math/big"
+	"strings"
+)
+
+const (
+	randNumberChars = "0123456789"
+	randLetterChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+)
+
+func generateValues(str string, n int, upper bool) string {
+	if n <= 0 {
+		return ""
+	}
+
+	sb := strings.Builder{}
+	sb.Grow(n)
+	bigInt := big.NewInt(int64(len(str)))
+	for i := 0; i < n; i++ {
+		randomInt, _ := rand.Int(rand.Reader, bigInt)
+		sb.WriteByte(str[randomInt.Int64()])
+	}
+	s := sb.String()
+	if upper {
+		s = strings.ToUpper(s)
+	}
+	return s
+}
+
+// Letter Generate letter rand string
+func Letter(n int, upper bool) string {
+	return generateValues(randLetterChars, n, upper)
+}
+
+// Number Generate number rand string
+func Number(n int) string {
+	return generateValues(randNumberChars, n, false)
+}
+
+// Any Generate number and letter combined string
+func Any(n int) string {
+	return generateValues(randLetterChars+randNumberChars, n, false)
+}