Many examples exist within the Reflection documentation, typically within the __construct documentation for each class.
Example #1 Reflection Example from Shell (a Terminal)
$ php --rf strlen $ php --rc finfo $ php --re json $ php --ri dom
The above example will output something similar to:
Function [ <internal:Core> function strlen ] {
  - Parameters [1] {
    Parameter #0 [ <required> $str ]
  }
}
Class [ <internal:fileinfo> class finfo ] {
  - Constants [0] {
  }
  - Static properties [0] {
  }
  - Static methods [0] {
  }
  - Properties [0] {
  }
  - Methods [4] {
    Method [ <internal:fileinfo, ctor> public method finfo ] {
      - Parameters [2] {
        Parameter #0 [ <optional> $options ]
        Parameter #1 [ <optional> $arg ]
      }
    }
    Method [ <internal:fileinfo> public method set_flags ] {
      - Parameters [1] {
        Parameter #0 [ <required> $options ]
      }
    }
    Method [ <internal:fileinfo> public method file ] {
      - Parameters [3] {
        Parameter #0 [ <required> $filename ]
        Parameter #1 [ <optional> $options ]
        Parameter #2 [ <optional> $context ]
      }
    }
    Method [ <internal:fileinfo> public method buffer ] {
      - Parameters [3] {
        Parameter #0 [ <required> $string ]
        Parameter #1 [ <optional> $options ]
        Parameter #2 [ <optional> $context ]
      }
    }
  }
}
Extension [ <persistent> extension #23 json version 1.2.1 ] {
  - Constants [10] {
    Constant [ integer JSON_HEX_TAG ] { 1 }
    Constant [ integer JSON_HEX_AMP ] { 2 }
    Constant [ integer JSON_HEX_APOS ] { 4 }
    Constant [ integer JSON_HEX_QUOT ] { 8 }
    Constant [ integer JSON_FORCE_OBJECT ] { 16 }
    Constant [ integer JSON_ERROR_NONE ] { 0 }
    Constant [ integer JSON_ERROR_DEPTH ] { 1 }
    Constant [ integer JSON_ERROR_STATE_MISMATCH ] { 2 }
    Constant [ integer JSON_ERROR_CTRL_CHAR ] { 3 }
    Constant [ integer JSON_ERROR_SYNTAX ] { 4 }
  }
  - Functions {
    Function [ <internal:json> function json_encode ] {
      - Parameters [2] {
        Parameter #0 [ <required> $value ]
        Parameter #1 [ <optional> $options ]
      }
    }
    Function [ <internal:json> function json_decode ] {
      - Parameters [3] {
        Parameter #0 [ <required> $json ]
        Parameter #1 [ <optional> $assoc ]
        Parameter #2 [ <optional> $depth ]
      }
    }
    Function [ <internal:json> function json_last_error ] {
      - Parameters [0] {
      }
    }
  }
}
dom
DOM/XML => enabled
DOM/XML API Version => 20031129
libxml Version => 2.7.3
HTML Support => enabled
XPath Support => enabled
XPointer Support => enabled
Schema Support => enabled
RelaxNG Support => enabled