在在C字节获得字符串大小 [英] get string size in bytes in c

问题描述

正如标题所暗示的，你能告诉我如何得到一个字符串（空终止）的规模保持在一个字符数组c ？这是很好的使用的sizeof 如果我宣布它（串）的功能，而不的malloc init或如果我宣布它作为指针？如果我用的malloc 初始化呢？我想有这个问题的详尽答复。

As the title imply, can you tell me how to get the size of a string (null terminated) kept in a char array in c? It's good to use sizeof if I declared it (the string) in a function without malloc init or if I declared it as a pointer? What if I initialized it with malloc? I would like to have an exhaustive response to that question.

推荐答案

您可以使用 strlen的。大小由终止空字符决定的，因此传入的参数应该是有效的。

You can use strlen. Size is determined by the terminating null-character, so passed string should be valid.

如果你想要得到的内存缓冲区的大小，包含您的字符串，你必须指向它的指针：

If you want to get size of memory buffer, that contains your string, and you have pointer to it:

• 如果它是动态阵列（使用malloc创建的），这是不可能得到
  它的大小，因为编译器不知道指针正指向。
  （<一href=\"http://stackoverflow.com/questions/492384/how-to-find-the-sizeofa-pointer-pointing-to-an-array\">check这）


• 如果是静态数组，可以使用的sizeof 来获得它的大小。

• If it is dynamic array(created with malloc), it is impossible to get it size, since compiler doesn't know what pointer is pointing at. (check this)
• If it is static array, you can use sizeof to get its size.

如果你感到困惑的动态和静态数组之间的差异，请这个。

If you are confused about difference between dynamic and static arrays, check this.

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