Read as a question mark, pinyin wèn hào is a punctuation mark, which is generally at the end of a question. Question mark is an auxiliary symbol tool of mood and intonation, which indicates the pause and tone after a sentence is finished. Used at the end of questions, rhetorical questions and rhetorical questions. Question marks are used at the end of interrogative sentences and rhetorical questions. Question marks generally do not appear at the head of a line. So, if you have eaten? .

The function of question mark in computer programming. It can be put in the middle in C language. With a question mark, you can determine the range of the type you want at compile time to avoid knowing that the type is wrong at run time. After adding a question mark, there is both flexibility and certainty, that is, change is unchangeable, change should be changed, and change should be unchanged. This is the so-called "holding on to the classics and achieving change", the golden mean of our ancestors, which is the case. It can be seen that the software field is also in line with this truth.