Attempt to de-reference a null object when using alternative to getGlobalDescribe

In the following code

String myString = 'Account'; 
SObjectType sObjType = ((SObject) Type.forName(myString).newInstance()).getSObjectType();

When myString = a object name does not exist i get a NullPointerException: Attempt to de-reference a null object.

Is there any way to check this before getting this error without using Schema.getGlobalDescribe() ?

speed comparison between above and getXXDescribe methods

String myString = 'InvalidClass'; 
Type classType = Type.forName(myString);

SObjectType sObjType;

if (classType != null) {
    sObjType = ((SObject) classType.newInstance()).getSObjectType();
}