add function randomNumber

index.js

@@ -117,6 +117,22 @@ module.exports = {
     return parseInt(port)
   },
 
+  randomNumber ({ length, min, max } = {}) {
+    // 长度为 length 的随机数字，或者 (min||0) <= num < max
+    var num = 0
+    if (typeof length === 'number' && length > 0) {
+      num = parseInt(Math.random() * Math.pow(10, length))
+      num = num.toString().padStart(length, '0')
+    } else if (typeof max === 'number' && max > 0) {
+      min = typeof min === 'number' && min >= 0 ? min : 0
+      num = parseInt(Math.random() * (max - min)) + min
+    } else {
+      // 如果 option 为空
+      num = Math.random()
+    }
+    return num
+  },
+
   /**
    * 用户编号转邀请码
    *
@@ -125,7 +141,7 @@ module.exports = {
    * @return {*}
    * @memberof TICrypto
    */
-  aiid2regcode(aiid) {
+  aiid2regcode (aiid) {
     const alphabet = 'e5fcdg3hqa4b1n0pij2rstuv67mwx89klyz'
     const base = 16367
     let num = (aiid + base) * (base - alphabet.length)
@@ -147,7 +163,7 @@ module.exports = {
    * @return {*}
    * @memberof TICrypto
    */
-  regcode2aiid(code) {
+  regcode2aiid (code) {
     if (typeof code === 'string' && /^[a-zA-Z0-9]+$/.test(code)) {
       const alphabet = 'e5fcdg3hqa4b1n0pij2rstuv67mwx89klyz'
       const base = 16367