Javascript 'require()' 方法

Question

在 python 中，当你导入一个模块时，里面的语句 导入模块的“if name == main” block 未执行。

是否有任何等效的方法可以防止在 javascript 的导入模块中执行不需要的语句？

Answer 1

通过fuyushimoya的评论。

When a file is run directly from Node, require.main is set to its module. That means that you can determine whether a file has been run directly by testing

require.main === module

For a file foo.js, this will be true if run via node foo.js, but false if run by require('./foo').

— Node.js documentation

所以:

if (require.main === module) {
    // Code that runs only if the module is executed directly
} else {
    // Code that runs only if the code is loaded as a module
}