closes loiane#13

Author: loiane

chapter07/07-HashCollisionLinearProbing.js

@@ -46,10 +46,10 @@ function HashLinearProbing(){
                 return table[position].value;
             } else {
                 var index = ++position;
-                while (table[index] === undefined || table[index].key !== key){
+                while (table[index] !== undefined && (table[index] && table[index].key !== key)){
                     index++;
                 }
-                if (table[index].key === key) {
+                if (table[index] && table[index].key === key) {
                     return table[index].value;
                 }
             }
@@ -82,4 +82,4 @@ function HashLinearProbing(){
             }
         }
     };
-}
+}