**Inheritance:**
java.lang.Object, com.aspose.tasks.PropertyCollection

**All Implemented Interfaces:**
java.util.Collection
```
public abstract class PropertyKeyedCollection<T> extends PropertyCollection<T> implements Collection<T>
```

A base class of collection of properties.

 T : he type of property.
## Methods

| Method | Description |
| --- | --- |
| [&lt;T1&gt;toArray(T1[] a)](#-T1-toArray-T1---) | \{@inheritDoc\} |
| [add(T item)](#add-T-) | Creates a new custom property. |
| [addAll(Collection&lt;? extends T&gt; c)](#addAll-java.util.Collection---extends-T--) | \{@inheritDoc\} |
| [clear()](#clear--) | \{@inheritDoc\} |
| [contains(Object item)](#contains-java.lang.Object-) | \{@inheritDoc\} |
| [contains(String name)](#contains-java.lang.String-) | Determines whether the Aspose.Tasks.Properties.PropertyCollection&lt;T&gt; contains a property with the specified name. |
| [containsAll(Collection&lt;?&gt; c)](#containsAll-java.util.Collection----) | \{@inheritDoc\} |
| [getNames()](#getNames--) | Gets the collection of all property names. |
| [get_Item(String name)](#get-Item-java.lang.String-) | Gets the Property associated with the specified key. |
| [isEmpty()](#isEmpty--) | \{@inheritDoc\} |
| [isReadOnly()](#isReadOnly--) | Gets a value indicating whether this collection is read-only; otherwise, false. |
| [remove(Object item)](#remove-java.lang.Object-) | \{@inheritDoc\} |
| [removeAll(Collection&lt;?&gt; c)](#removeAll-java.util.Collection----) | \{@inheritDoc\} |
| [retainAll(Collection&lt;?&gt; c)](#retainAll-java.util.Collection----) | \{@inheritDoc\} |
| [size()](#size--) | Gets the number of properties in the collection. |
| [toArray()](#toArray--) | \{@inheritDoc\} |
### &lt;T1&gt;toArray(T1[] a) {#-T1-toArray-T1---}
```
public T1[] <T1>toArray(T1[] a)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| a | T1[] | \{@inheritDoc\} |

**Returns:**
T1[] - \{@inheritDoc\}
### add(T item) {#add-T-}
```
public final boolean add(T item)
```


Creates a new custom property.

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| item | T | The property to add. |

**Returns:**
boolean
### addAll(Collection&lt;? extends T&gt; c) {#addAll-java.util.Collection---extends-T--}
```
public boolean addAll(Collection<? extends T> c)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| c | java.util.Collection&lt;? extends T&gt; | \{@inheritDoc\} |

**Returns:**
boolean - \{@inheritDoc\}
### clear() {#clear--}
```
public void clear()
```




### contains(Object item) {#contains-java.lang.Object-}
```
public final boolean contains(Object item)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| item | java.lang.Object |  |

**Returns:**
boolean
### contains(String name) {#contains-java.lang.String-}
```
public final boolean contains(String name)
```


Determines whether the Aspose.Tasks.Properties.PropertyCollection&lt;T&gt; contains a property with the specified name.

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| name | java.lang.String | The name of a property |

**Returns:**
boolean - true if the Aspose.Tasks.Properties.PropertyCollection&lt;T&gt; contains a property with the specified name; otherwise, false.
### containsAll(Collection&lt;?&gt; c) {#containsAll-java.util.Collection----}
```
public boolean containsAll(Collection<?> c)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| c | java.util.Collection&lt;?&gt; | \{@inheritDoc\} |

**Returns:**
boolean - \{@inheritDoc\}
### getNames() {#getNames--}
```
public final Collection<String> getNames()
```


Gets the collection of all property names.

**Returns:**
java.util.Collection&lt;java.lang.String&gt; - the collection of all property names.
### get_Item(String name) {#get-Item-java.lang.String-}
```
public final T get_Item(String name)
```


Gets the Property associated with the specified key.

**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| name | java.lang.String | The name of the Property to get. |

**Returns:**
T - The Property associated with the specified name.
### isEmpty() {#isEmpty--}
```
public boolean isEmpty()
```




**Returns:**
boolean - \{@inheritDoc\}
### isReadOnly() {#isReadOnly--}
```
public abstract boolean isReadOnly()
```


Gets a value indicating whether this collection is read-only; otherwise, false.

**Returns:**
boolean - a value indicating whether this collection is read-only; otherwise, false.
### remove(Object item) {#remove-java.lang.Object-}
```
public final boolean remove(Object item)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| item | java.lang.Object | \{@inheritDoc\} |

**Returns:**
boolean - \{@inheritDoc\}
### removeAll(Collection&lt;?&gt; c) {#removeAll-java.util.Collection----}
```
public boolean removeAll(Collection<?> c)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| c | java.util.Collection&lt;?&gt; | \{@inheritDoc\} |

**Returns:**
boolean - \{@inheritDoc\}
### retainAll(Collection&lt;?&gt; c) {#retainAll-java.util.Collection----}
```
public boolean retainAll(Collection<?> c)
```




**Parameters:**
| Parameter | Type | Description |
| --- | --- | --- |
| c | java.util.Collection&lt;?&gt; | \{@inheritDoc\} |

**Returns:**
boolean - \{@inheritDoc\}
### size() {#size--}
```
public final int size()
```


Gets the number of properties in the collection.

**Returns:**
int - the number of properties in the collection.
### toArray() {#toArray--}
```
public Object[] toArray()
```




**Returns:**
java.lang.Object[] - \{@inheritDoc\}