Asserts that the [code]condition[/code] is [code]true[/code]. If the [code]condition[/code] is [code]false[/code], an error is generated. When running from the editor, the running project will also be paused until you resume it. This can be used as a stronger form of [method push_error] for reporting errors to project developers or add-on users. [b]Note:[/b] For performance reasons, the code inside [method assert] is only executed in debug builds or when running the project from the editor. Don't include code that has side effects in an [method assert] call. Otherwise, the project will behave differently when exported in release mode. The optional [code]message[/code] argument, if given, is shown in addition to the generic "Assertion failed" message. You can use this to provide additional details about why the assertion failed. [codeblock] # Imagine we always want speed to be between 0 and 20. var speed = -10 assert(speed < 20) # True, the program will continue assert(speed >= 0) # False, the program will stop assert(speed >= 0 and speed < 20) # You can also combine the two conditional statements in one check assert(speed < 20, "speed = %f, but the speed limit is 20" % speed) # Show a message with clarifying details [/codeblock]
[b]Note:[/b] For performance reasons, the code inside [method assert] is only executed in debug builds or when running the project from the editor. Don't include code that has side effects in an [method assert] call. Otherwise, the project will behave differently when exported in release mode.
The optional [code]message[/code] argument, if given, is shown in addition to the generic "Assertion failed" message. You can use this to provide additional details about why the assertion failed.
[codeblock]
# Imagine we always want speed to be between 0 and 20.
var speed = -10
assert(speed < 20) # True, the program will continue
assert(speed >= 0) # False, the program will stop
assert(speed >= 0 and speed < 20) # You can also combine the two conditional statements in one check
assert(speed < 20, "speed = %f, but the speed limit is 20" % speed) # Show a message with clarifying details
[/codeblock]
追加の引数 [code]message[/code] は、与えられたときは、規定の「アサート失敗」メッセージにそれを追加して表示します。これはアサートが失敗した理由について、より詳しい情報を加えたいときに使えます。
[codeblock]
# speedを 0 から 20 の間に制限したいとします
speed = -10
assert(speed < 20) # 真。プログラムは続行します
assert(speed >= 0) # 偽。プログラムは停止します
assert(speed >= 0 && speed < 20) # ふたつの文をひとつにまとめられます
assert(speed < 20, "speed = %f ですが、スピード制限は 20 です" % speed) # より詳細なメッセージを表示します
[/codeblock]