Which of the following statements is incorrect ?

Question

BlackTom AI · Accepted Answer

The incorrect statement is "__str__() is only executable for one Python object" because __str__ is a class-level special method used by str() and print() for any instance of that class, not restricted to a single object. 1) Relevant knowledge points and concepts - Python special (dunder) methods: __str__ is defined on a class (or its type) to provide a human-readable string representation. str(obj) and print(obj) call the object's class __str__. - Method lookup: Python looks for special method implementations on the object's type (class), so defining __str__ on the class affects all its instances. - Java Object.toString(): Every Java class inherits toString() from java.lang.Object; classes can override it to provide useful information. - Java variable declaration syntax: " ;" (e.g., int x;) is a correct declaration. - Python variables are dynamically typed and can reference values of any type. 2) Step-by-step reasoning - If you define class C with def __str__(self): return "C", then for any instance c = C(), str(c) or print(c) will call C.__str__ and produce "C". That demonstrates __str__ applies to all instances of the class. - Since special methods are normally resolved on the class, you cannot make __str__ apply to only a single instance by setting an instance attribute named __str__ (Python ignores instance-level special-method attributes for many operations). - Therefore, the claim that __str__ is only executable for one Python object is false. 3) Calculations - Not applicable. 4) Why the correct answer is correct - The statement is incorrect because __str__ is a class-defined special method used by any instance of that class; it's not limited to one object. 5) Why other options are correct - "toString() provides information about all Java objects": true in the sense every Java object has a toString() method inherited from Object (though classes may override it). - " ; is the correct variable declaration in Java": true (e.g., int x;). - "A variable in python can store any data type": true because Python is dynamically typed. 6) Conclusion The incorrect option is "__str__() is only executable for one Python object", which matches the provided answer.

Which of the following statements is incorrect ?单项选择题

类似问题

Referring to an objects TYPE is the same as referring to its:

Classes have:

An object is a bundle of data (attributes) together with operations that act (operate) on:

The relationship between a building and a locker classes in UTS library system is :

Objects have:

Consider the following Java code: What is the output of running:

The main difference between a field and a class variable is that:

An advantage of composition is the fact that we can sometimes reuse classes that we have already written, instead of having to design and write new classes.

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单