Webb13 apr. 2024 · 对于单纯变量，最好以 const 对象或 enum 替换 #define 。. 对于形似函数的宏（ macro ），最好改用 inline 函数替换 #define 。. ASPECT_RATIO 有可能并未进入记号表内，编译器并未开始处理就被预处理器移走。. 如果此变量出现编译错误，错误信息可能只提到1.653， 而不是 ... Webb31 juli 2010 · Add a comment. 2. Unless the values of the constants are pretty weird (i.e. you have constants set to nil or false ), the best choice would be to use the conditional assignment operator: Tau = 2*Pi. This will set Tau to 2π if it is nil, false or undefined, and leave it alone otherwise. Share.

Everything You Need to Know About Ruby Constants

Webb但是，您可以使用const int EXAMPLE=12，然后可以在标准printf方法中使用EXAMPLE，例如printf（“%d\n”，EXAMPLE） 您在最后3行中使用的 WebbThis means that ruby first looks for the constant in the executing code's module (or class), then moves outward to each successive enclosing module (or class) until it finds the … p und alpha

class Module - RDoc Documentation - Ruby doc

Webb31 juli 2010 · Unfortunately, it's not very portable: depending on the ruby version and implementation (ruby/jruby), the affectation to a constant with = gave me three … Webbconst_defined?(name, inherit = true) -> bool モジュールに name で指定される名前の定数が定義されている時真を返します。 スーパークラスや include したモジュールで定義さ … WebbConversely, if you have a null-terminated char*, you can use rb_str_new_cstr () to create a Ruby String. And if you want your String to contain nulls, use rb_str_new () which takes a char* and the string’s length (as a long ). The encodings of these strings will be ASCII-8BIT, which is often undesirable in Ruby. pundc aktionscode