This document details changes between AutoHotkey v1.0 and v1.1 that may cause scripts to behave differently, and therefore might be important to keep in mind while reading or updating old code. See also: Changes from v1.1 to v2.0.
AutoHotkey v1.1 is also known as "AutoHotkey_L", while AutoHotkey v1.0 was retrospectively labelled "AutoHotkey Basic". Some older versions of AutoHotkey_L used 1.0.* version numbers, so for clarity, this document refers to the two branches of AutoHotkey by name rather than version number.
High impact:
Medium impact:
x & y:: causes both x:: and x up:: to fire when x is releasedLow impact:
Certain syntax errors which were tolerated by AutoHotkey Basic are not tolerated by AutoHotkey_L. Most such errors can be easily corrected once they are identified. Some errors are detected at load-time, and must be corrected before the script will run at all. Other errors are raised only when specific conditions are met while the script is running.
Error detection in v2.0 is generally more robust, and as there have been numerous changes to usage beyond just error detection and handling, the differences in error detection between v1.0 and v1.1 are not listed here. For those details, refer to the v1.1 documentation.
FileRead translates text between code pages in certain common cases and therefore might output corrupt binary data. To avoid this in v2.0, add the RAW option or use FileOpen instead.
The characters [, ] and ? are reserved for use in expressions, so are no longer valid in variable names. Consequently, ? (used in ternary operations) no longer requires a space on either side. Code for v1.0 which uses these characters in a variable name would have a new interpretation in v1.1, and as such might not be detected as an error.
Related: Operators for Objects, Names (Changes from v1.1 to v2.0)
DPI scaling is enabled by default for script GUIs to ensure they scale according to the system DPI setting. If enabled and the system DPI setting is not 96 (100 %), positions and sizes accepted by or returned from Gui methods/properties are not compatible with other functions. To disable DPI scaling, use MyGui.Opt("-DPIScale").
Some Transform sub-commands are altered or unavailable:
Transform itself was removed in v2.0.
When AutoHotkey_L is launched without specifying a script, an .ahk file is loaded by default instead of an .ini file. The name of this file depends on the filename of the current executable. For more details, see Script Filename.
When an uppercase H is used, hexadecimal digits A-F will also be in uppercase. AutoHotkey Basic always produces lowercase digits.
SetFormat itself was removed in v2.0. Format("0x{:x}", n) produces lowercase a-f while Format("0x{:X}", n) produces uppercase A-F.
The following commands now set A_LastError to assist with debugging: FileAppend, FileRead, FileReadLine, FileDelete, FileCopy, FileMove, FileGetAttrib/Time/Size/Version, FileSetAttrib/Time, FileCreateDir, RegRead, RegWrite, RegDelete. Using any of these commands causes the previous value of A_LastError to be overwritten.
For v2.0, A_LastError is also set by IniRead, IniWrite and IniDelete.
MsgBox in v1.0 and v1.1 had "smart comma handling" to avoid the need to escape commas in unquoted text. This handling was slightly different between the two versions, and might need to be taken into account in very rare cases while reading v1.0 code. Refer to the v1.1 documentation for details. v2.0 uses expression syntax exclusively and as such has no need for any special handling of commas.
Applying the +Owner option to a Gui also removes the WS_CHILD style and sets the WS_POPUP style. This may break scripts which used +Owner to set the parent window of a Gui after setting the styles.
As of v1.1.14, the tilde prefix affects how a key works when used as a modifier key in a custom combination.
Except when the tilde prefix is used, if both a key-down and a key-up hotkey are defined for a custom modifier key, they will both fire when the key is released. For example, x & y:: causes both x:: and x up:: to fire when x is released, where previously x:: never fired.
If Var is [not] Type identified certain (possibly locale-specific) non-ASCII characters as alphabetic/uppercase/lowercase by default in v1.0, whereas it did so in v1.1 only if StringCaseSense Locale was used. Similarly, the IsType functions in v2.0 only identify non-ASCII characters as alphabetic if the second parameter is "Locale".
GroupActivate sets ErrorLevel only in v1.1, not v1.0 or v2.0.
GroupAdd's Label parameter behaves differently between v1.0 and v1.1, but was removed in v2.0.
AutoHotkey_L includes some enhancements to the way the Run and RunWait commands interpret the Target parameter. This allows some things that didn't work previously, but in some very rare cases, may also affect scripts which were already working in AutoHotkey Basic. The new behaviour is as follows:
Loop Read and File.ReadLine no longer interpret the character Ctrl+Z (0x1A) as an end-of-file marker. Any Ctrl+Z, even one appearing at the very end of the file, is loaded as-is. FileRead already ignored this character, so is not affected by this issue.
If the script has not been compiled, A_IsCompiled is defined even if the script has not been compiled; its value is "" in v1.1 and 0 in v2.0. Previously it was left undefined, which meant that assignments such as A_IsCompiled := 1 were valid if the script hadn't been compiled. Now it is treated as a read-only built-in variable in all cases.
When the function name given to DllCall cannot be resolved, AutoHotkey_L automatically appends an "A" (ANSI) or "W" (Unicode) to the function name regardless of which DLL was specified. By contrast, AutoHotkey Basic appends the "A" suffix only for functions in User32.dll, Kernel32.dll, ComCtl32.dll, or Gdi32.dll.