Update README.md

README.md

@@ -60,6 +60,7 @@ See something incorrectly described, buggy or outright wrong? Open an issue or s
  * [Random array element](#random-array-element)
  * [Cycle through an array](#cycle-through-an-array)
  * [Toggle between two values](#toggle-between-two-values)
+ * [join string into lists](#join-string-into-lists)
 * [LOOPS](#loops)
  * [Loop over a range of numbers](#loop-over-a-range-of-numbers)
  * [Loop over a variable range of numbers](#loop-over-a-variable-range-of-numbers)
@@ -759,6 +760,43 @@ cycle() {
 }
 ```
 
+## join string into lists
+
+This function is same to the python' function `join` or perl function `join`.
+
++ function
+
+```bash
+function join_list {
+ local delimiter=$1
+ local list=($@)
+ echo ${list[@]}
+ local len=${#list[@]}
+ (( tail_1 = $len - 1 ))
+ (( tail_2 = $len - 2 ))
+ if [ ${len} -gt 1 ];
+ then
+ for i in $(seq 0 ${tail_2});
+ do
+ local item=${list[${i}]}
+ echo -n ${item}${delimiter}
+ done
+ echo ${list[${tail_1}]}
+ else
+ echo ${list[0]}
+ fi
+}
+```
+
++ usage
+
+```bash
+$ l=$(seq 0 10)
+$ join_list , ${l[@]}
+
+0,1,2,3,4,5,6,7,8,9,10
+```
+
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