add sound switch

server/src/app/controller/foo.js

@@ -0,0 +1,23 @@
+
+function convertBase( numberString, fromBase, toBase ) {
+  let numberToTen = toTen(numberString, fromBase)
+  let str = ''
+  while (numberToTen) {
+    let toNumber = numberToTen % toBase.base
+    str += toBase.map[toNumber]
+    numberToTen = Math.floor(numberToTen / toBase.base)
+  }
+  return str
+}
+
+function toTen(numberString, fromBase) {
+  let baseMap = fromBase.map.split('')
+  let numberArr = numberString.split('')
+  let sum = 0
+  for (let i = 0; i <= numberArr.length - 1; i++) {
+    let currNumber = numberArr[i]
+    let baseIndex = baseMap.findIndex(b => b === currNumber)
+    sum += ((baseIndex + 1) * fromBase.base ** (numberArr.length - 1 - i))
+  }
+  return sum
+}