指针数组

本文介绍了指针数组的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 嗨 关于指针数组的问题。 以下是一个21元素的数组，每个都是一个指针 或者这是一个指向ONE数组的指针（听起来很奇怪）： double * ydata [21]; 假设这是21个指针我如何初始化 它们指向null？这是错的： ，i = 0; i = 20 i ++ ydata [i] = NULL; 并稍后在某处分配新的 for I = 0; i = 20 i ++ ydata [i] = new double [1000]; 这曾经在C中工作，但不适用于C ++！ 分配新的后我试试这个： for（int i = 0; i< 1000; i ++）{ ydata [0] [i] = double （rev_data [i]）; 它只是崩溃。 为你的帮助提供 Kamran 解决方案 请参阅多维阵列上的faq部分 Raj AFAIR T * p [n]; //数组T * T（* p）[n]; //指针T [n] * Henrietta Denoue： 嗨 以下是一个21元素数组，每个都是一个指针或者这是一个指向ONE数组的指针（听起来很奇怪） double * ydata [21]; 一个21元素的数组，每个元素都是一个指针。 假设这是21个指针我如何初始化他们指向null？这是错的： 对于i = 0; i = 20 i ++ ydata [i] = NULL; 是的，这是错误的，无论是语法上（它不是C ++）还是意图。 最简单的方式是 double * ydata [21] = {}; 并分配新的某处后来 对于i = 0; i = 20 i ++ ydata [i] = new double [1000]; 这曾经在C中工作，但不适用于C ++！ 从来没有用过C语言，它既不是C语言也不是C ++语法。 分配新语后我试试这个： for（int i = 0; i< 1000; i ++）{ ydata [0] [i] = double（rev_data [i]）; At只是崩溃了。 将该循环与之前的循环进行比较。 - 答：因为它弄乱了人们通常阅读文字的顺序。 问：为什么这么糟糕？ A：热门发布。 问：usenet和电子邮件中最烦人的事情是什么？ Hi A question about array of pointers. Is the following an 21 element array, each a pointeror is this a pointer to ONE array (strange as it sounds): double* ydata[21]; And supposing this to be 21 pointers how do I initializethem to point to null ? Is this wrong: for i=0; i=20 i++ydata[i] = NULL; and to allocate new somewhere later for i=0; i=20 i++ydata[i] = new double[1000];This used to work in C but doesn''t with C++ !After allocating new I try this:for (int i = 0; i < 1000; i++) {ydata[0][i] = double(rev_data[i]);At it just crashes.Thaks for your help Kamran 解决方案 please see the faq section on multi-dimensional arrayRaj AFAIRT *p[n]; //array of T*T (*p)[n]; //pointer to T[n]* Henrietta Denoue: Hi A question about array of pointers. Is the following an 21 element array, each a pointer or is this a pointer to ONE array (strange as it sounds) double* ydata[21];A 21 element array, each element a pointer. And supposing this to be 21 pointers how do I initialize them to point to null ? Is this wrong: for i=0; i=20 i++ ydata[i] = NULL; Yes, that is wrong, both syntactically (it''s not C++) and in intent. Easiest way is double* ydata[21] = {}; and to allocate new somewhere later for i=0; i=20 i++ ydata[i] = new double[1000]; This used to work in C but doesn''t with C++ !That has never worked in C, it''s neither C nor C++ syntax. After allocating new I try this: for (int i = 0; i < 1000; i++) { ydata[0][i] = double(rev_data[i]); At it just crashes. Compare that loop to the previous ones. --A: Because it messes up the order in which people normally read text.Q: Why is it such a bad thing?A: Top-posting.Q: What is the most annoying thing on usenet and in e-mail? 这篇关于指针数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！