updated notes

src/rhcsa.md

@@ -357,3 +357,34 @@ else
   echo "The file '$user_file' does not exist."
 fi
 ```
+
+### for loop
+```bash
+#!/bin/bash
+
+for i in 1..10; do
+    echo $i
+done
+```
+
+### while loop
+```bash
+#!/bin/bash
+
+i=1
+while [ $i -le 10 ]; do
+    echo $i
+    i=$((i+1))
+done
+```
+
+### until loop
+```bash
+#!/bin/bash
+
+i=1
+until [ $i -gt 10 ]; do
+    echo $i
+    i=$((i+1))
+done
+```