Added isString() method

README.md

@@ -190,6 +190,7 @@ will return:
 <a href="#isnumeric">isNumeric</a>
 <a href="#isobject">isObject</a>
 <a href="#isscalar">isScalar</a>
+<a href="#isstring">isString</a>
 <a href="#join">join</a>
 <a href="#jsonserialize">jsonSerialize</a>
 <a href="#keys">keys</a>
@@ -413,6 +414,7 @@ will return:
 * [isNumeric()](#isnumeric) : Tests if all entries are numeric values
 * [isObject()](#isobject) : Tests if all entries are objects
 * [isScalar()](#isscalar) : Tests if all entries are scalar values.
+* [isString()](#isstring) : Tests if all entries are string values.
 * [implements()](#implements) : Tests if all entries are objects implementing the interface
 * [none()](#none) : Tests if none of the elements are part of the map
 * [some()](#some) : Tests if at least one element is included
@@ -3103,6 +3105,48 @@ Map::from( [[1]] )->isScalar();
 ```
 
 
+### isString()
+
+Determines if all entries are string values.
+
+```php
+public function isString() : bool
+```
+
+* @return **bool** TRUE if all map entries are string values, FALSE if not
+
+**Examples:**
+
+```php
+Map::from( ['abc'] )->isString();
+// true
+
+Map::from( [] )->isString();
+// true
+
+Map::from( [1] )->isString();
+// false
+
+Map::from( [1.1] )->isString();
+// false
+
+Map::from( [true, false] )->isString();
+// false
+
+Map::from( [new stdClass] )->isString();
+// false
+
+Map::from( [resource] )->isString();
+// false
+
+Map::from( [null] )->isString();
+// false
+
+Map::from( [[1]] )->isString();
+// false
+```
+
+
 ### join()
 
 Concatenates the string representation of all elements.

src/Map.php

@@ -2535,16 +2535,14 @@ public function isEmpty() : bool
 	 */
 	public function isNumeric() : bool
 	{
-		$result = true;
-
 		foreach( $this->list() as $val )
 		{
 			if( !is_numeric( $val ) ) {
-				$result = false;
+				return false;
 			}
 		}
 
-		return $result;
+		return true;
 	}
 
 
@@ -2563,16 +2561,14 @@ public function isNumeric() : bool
 	 */
 	public function isObject() : bool
 	{
-		$result = true;
-
 		foreach( $this->list() as $val )
 		{
 			if( !is_object( $val ) ) {
-				$result = false;
+				return false;
 			}
 		}
 
-		return $result;
+		return true;
 	}
 
 
@@ -2597,16 +2593,46 @@ public function isObject() : bool
 	 */
 	public function isScalar() : bool
 	{
-		$result = true;
-
 		foreach( $this->list() as $val )
 		{
 			if( !is_scalar( $val ) ) {
-				$result = false;
+				return false;
 			}
 		}
 
-		return $result;
+		return true;
+	}
+
+
+	/**
+	 * Determines if all entries are string values.
+	 *
+	 * Examples:
+	 *  Map::from( ['abc'] )->isString();
+	 *  Map::from( [] )->isString();
+	 *  Map::from( [1] )->isString();
+	 *  Map::from( [1.1] )->isString();
+	 *  Map::from( [true, false] )->isString();
+	 *  Map::from( [new stdClass] )->isString();
+	 *  Map::from( [#resource] )->isString();
+	 *  Map::from( [null] )->isString();
+	 *  Map::from( [[1]] )->isString();
+	 *
+	 * Results:
+	 *  The first two examples return TRUE while the others return FALSE
+	 *
+	 * @return bool TRUE if all map entries are string values, FALSE if not
+	 */
+	public function isString() : bool
+	{
+		foreach( $this->list() as $val )
+		{
+			if( !is_string( $val ) ) {
+				return false;
+			}
+		}
+
+		return true;
 	}
 
 

tests/MapTest.php

@@ -1846,6 +1846,20 @@ public function testIsScalar()
 	}
 
 
+	public function testIsString()
+	{
+		$this->assertTrue( Map::from( [] )->isString() );
+		$this->assertTrue( Map::from( ['abc'] )->isString() );
+
+		$this->assertFalse( Map::from( [1] )->isString() );
+		$this->assertFalse( Map::from( [1.1] )->isString() );
+		$this->assertFalse( Map::from( [true, false] )->isString() );
+		$this->assertFalse( Map::from( [new \stdClass] )->isString() );
+		$this->assertFalse( Map::from( [null] )->isString() );
+		$this->assertFalse( Map::from( [[1]] )->isString() );
+	}
+
+
 	public function testJoin()
 	{
 		$m = new Map( ['a', 'b', null, false] );