| Type |  | Name |  | Summary | 
|  | 
| Compiler Directive |  | $I |  | Allows code in an include file to be incorporated into a Unit | 
| Compiler Directive |  | $IfDef |  | Executes code if a conditional symbol has been defined | 
| Compiler Directive |  | $IfNDef |  | Executes code if a conditional symbol has not been defined | 
| Compiler Directive |  | $IfOpt |  | Tests for the state of a Compiler directive | 
| Compiler Directive |  | $Include |  | Allows code in an include file to be incorporated into a Unit | 
| Compiler Directive |  | $IOChecks |  | When on, an IO operation error throws an exception | 
| Keyword |  | If |  | Starts a conditional expression to determine what to do next | 
| Keyword |  | Implementation |  | Starts the implementation (code) section of a Unit | 
| Keyword |  | In |  | Used to test if a value is a member of a set | 
| Procedure |  | Inc |  | Increment an ordinal variable | 
| Function |  | IncDay |  | Increments a TDateTime variable by + or - number of  days | 
| Function |  | IncHour |  | Increments a TDateTime variable by + or - number of  hours | 
| Procedure |  | Include |  | Include a value in a set variable | 
| Function |  | IncMillisecond |  | Increments a TDateTime variable by + or - number of  milliseconds | 
| Function |  | IncMinute |  | Increments a TDateTime variable by + or - number of  minutes | 
| Function |  | IncMonth |  | Increments a TDateTime variable by a number of  months | 
| Function |  | IncSecond |  | Increments a TDateTime variable by + or - number of  seconds | 
| Function |  | IncYear |  | Increments a TDateTime variable by a number of  years | 
| Directive |  | Index |  | Principally defines indexed class data properties | 
| Constant |  | Infinity |  | Floating point value of infinite size | 
| Keyword |  | Inherited |  | Used to call the parent class constructor or destructor method | 
| Variable |  | Input |  | Defines the standard input text file | 
| Function |  | InputBox |  | Display a dialog that asks for user text input, with default | 
| Function |  | InputQuery |  | Display a dialog that asks for user text input | 
| Procedure |  | Insert |  | Insert a string into another string | 
| Function |  | Int |  | The integer part of a floating point number as a float | 
| Type |  | Int64 |  | A 64 bit sized integer - the largest in Delphi | 
| Type |  | Integer |  | The basic Integer type | 
| Keyword |  | Interface |  | Used for Unit external definitions, and as a Class skeleton | 
| Function |  | IntToHex |  | Convert an Integer into a hexadecimal string | 
| Function |  | IntToStr |  | Convert an integer into a string | 
| Function |  | IOResult |  | Holds the return code of the last I/O operation | 
| Keyword |  | Is |  | Tests whether an object is a certain class or ascendant | 
| Function |  | IsInfinite |  | Checks whether a floating point number is infinite | 
| Function |  | IsLeapYear |  | Returns true if a given calendar year is a leap year | 
| Function |  | IsMultiThread |  | Returns true if the code is running multiple threads | 
| Function |  | IsNaN |  | Checks to see if a floating point number holds a real number | 
|  |