add examples for join

snippets/join.md

@@ -1,11 +1,11 @@
 ### join
 
-
+Is like `Array.join()` but with an additional argument of `end`(is equal to `separator` by default) which is used to separate the second to last and last items in the array. Returns `""` when the array is empty and the first item when the length of array is 1.
 
 ```js
-const join = (arr,start = ',',end = start) => {
+const join = (arr,separator = ',',end = separator ) => {
       return arr.reduce((acc,val,i) => {
-       return  i == arr.length - 2 ? acc + val + end : i == arr.length - 1 ? acc + val : acc + val + start
+       return  i == arr.length - 2 ? acc + val + end : i == arr.length - 1 ? acc + val : acc + val + separator
      },'')
  }
 ```