add 242 solution[js]

Author: limbowandering

solution/242.Valid Anagram/Solution.js

@@ -0,0 +1,26 @@
+const isAnagram = function(s,t){
+  let a = {}, b = {};
+  for(let i = 0 ; i < s.length; i++){
+    if(a.hasOwnProperty(s[i])){
+      a[s[i]]++;
+    }else{
+      a[s[i]] = 1;
+    }
+  }
+  for(let i = 0 ; i < t.length; i++){
+    if(b.hasOwnProperty(t[i])){
+      b[t[i]]++;
+    }else{
+      b[t[i]] = 1;
+    }
+  }
+  let keyA = Object.keys(a);
+  let keyB = Object.keys(b);
+  if(keyA.length !== keyB.length){
+    return false;
+  }
+  for(let i = 0; i < keyA.length; i++){
+    if(a[keyA[i]] !== b[keyA[i]]) return false;
+  }
+  return true;
+}