auto c ++关键字有什么作用? [英] What does the auto c++ keyword do?

问题描述

我最近在c ++中遇到了关键字auto.

I recently came accross the keyword auto in c++.

在代码中:

auto maxIterator = std::max_element(&spec[0], &spec[sampleSize]);
float maxVol = *maxIterator;

// Normalize
if (maxVol != 0)
  std::transform(&spec[0], &spec[sampleSize], &spec[0], [maxVol] (float dB) -> float { return dB / maxVol; });

这与对音频流进行频率分析有关. 从网站上:

This is to do with running a frequency analysis on a audio stream. From the website: http://katyscode.wordpress.com/2013/01/16/cutting-your-teeth-on-fmod-part-4-frequency-analysis-graphic-equalizer-beat-detection-and-bpm-estimation/

我已经搜索了论坛，但是它说该关键字没有用.有人可以在这里解释它的用法.

I have searched the forums but It says that there is no use for the keyword. Could someone please explain the use of it here.

我对C ++还是很陌生，所以请尽量不要使答案过于复杂. 非常感谢.

I am quite new to c++ so please try not to make the answers too complicated. Thanks so much all.

是否也自动将maxIterator设置为指针?

Did auto make maxIterator a pointer also?

推荐答案

在C ++ 11中，关键字auto从其初始化表达式中推断出已声明变量的类型.因此，在您的代码中，它推导了maxIterator的类型.

In C++11, the keyword auto deduces the type of declared variable from its initialization expression. Hence, in your code it deduces type of maxIterator.

有关auto的更多信息，请在此处

For more information on auto look here

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