CODEWITHSUNDEEP
javaarraylist
Suhail Gupta
Suhail Gupta

Reputation: 23236

difference between the types of initialization of ArrayList

What is the difference between the two :

first :

ArrayList<String> linkList = new ArrayList<String>();

second :

ArrayList linkList = new ArrayList<String>();

Or is there any difference ?

Upvotes: 3

Views: 188

Answers (3)

saplingPro
saplingPro

Reputation: 21329

Also in the first case linkList is of type String and in the second case is of type Object.

Upvotes: 0

Keppil
Keppil

Reputation: 46219

ArrayList<String> linkList = new ArrayList<String>();

uses generics to ensure type safety.

ArrayList linkList = new ArrayList<String>();

doesn't. As @BruceMartin points out, this means that the lines 

linkList.add(0);
String element = (String) linkList.get(0);

gives a compile time error in the first case, but fails at runtime with the second declaration.

As another example, to get() a String from the two alternatives, the second variant would require a cast:
first: 

String element = linkList.get(0);

second: 

String element = (String) linkList.get(0);

Upvotes: 9

davidmontoyago
davidmontoyago

Reputation: 1833

At compile time: the first one uses generics, ensures type safety and code readability.

At runtime: they are the same.

Upvotes: 3

Related Questions