Update index.md (#29031)
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Manish Giri
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@ -10,11 +10,9 @@ title: ArrayList
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import java.util.ArrayList; // is more efficient than importing all of java.util
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import java.util.ArrayList; // is more efficient than importing all of java.util
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```
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```
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Always import the most specific package in order to save memory size and performance time.
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Always import the most specific package in order to save memory size and performance time.
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`ArrayList` is a class that is used to create dynamic arrays. It is slower than regular arrays but allows for a lot of manipulation. It should be initialized to have a specific size or it will have the default size of 10 units.
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`ArrayList` is a class that is used to create dynamic arrays. It is slower than regular arrays but allows for a lot of manipulation. It should be initialized to have a specific size or it will have the default size of 10 units.
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```java
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```java
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@ -22,7 +20,7 @@ title: ArrayList
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ArrayList<Integer> ages = new ArrayList<>(5);
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ArrayList<Integer> ages = new ArrayList<>(5);
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```
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```
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In the above snippet, the angle breackets `<>` take a generic data type as argument specifying data type of the elements in the ArrayList. The first ArrayList `names` is specified as containing *String* elements. Thus, it will only be allowed to contain String elements. Its size is not specified so it will have a default size of 10. The second ArrayList `ages` has specified that it will only hold integers. But ArrayList cannot hold primitives, it only holds objects. Thus to make it store integers, floats, etc., we can use wrapper classes. `names` will have a specified size of 5.
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In the above snippet, the angle brackets `<>` take a generic data type as argument specifying data type of the elements in the ArrayList. The first ArrayList `names` is specified as containing *String* elements. Thus, it will only be allowed to contain String elements. Its size is not specified so it will have a default size of 10. The second ArrayList `ages` has specified that it will only hold integers. But ArrayList cannot hold primitives, it only holds objects. Thus to make it store integers, floats, etc., we can use wrapper classes. `names` will have a specified size of 5.
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Since ArrayList implements *List*, an ArrayList can be created using the following syntax:
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Since ArrayList implements *List*, an ArrayList can be created using the following syntax:
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```java
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```java
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