array

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Consider: int[][] multD = new int[5][]; multD[0] = new int[10]; Is this how you create a two-dimensional array with 5 rows and 10 columns? I saw this code online, but the syntax didn't make sense. 回答1: Try the following: int[][] multi = new int[5][10]; ... which is a short hand for something like this: int[][] multi = new int[5][]; multi[0] = new int[10]; multi[1] = new int[10]; multi[2] = new int[10]; multi[3] = new int[10]; multi[4] = new int[10]; Note that every element will be initialized to the default value for int , 0 , so the above

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I want to dynamically allocate 1 dimension of a 2D array (the other dimension is given). Does this work: int NCOLS = 20; // nrows = user input... double *arr[NCOLS]; arr = (double *)malloc(sizeof(double)*nrows); and to free it: free(arr) 回答1: Not quite -- what you've declared is an array of pointers. You want a pointer to an array, which would be declared like this: double (*arr)[NCOLS]; Then, you'd allocate it like so: arr = malloc(nrows * sizeof(double[NCOLS])); It can then be treated as a normal nrows by NCOLS 2D array. To free it, just

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to implement a stack using an array but I receive an error. class Stack{ private: int cap; int elements[this->cap]; // <--- Errors here int top; public: Stack(){ this->cap=5; this->top=-1; }; The indicated line has these errors: Multiple markers at this line - invalid use of 'this' at top level - array bound is not an integer constant before ']' token What am I doing wrong? 回答1: In C++, the size of an array must be a constant known at compile-time. You'll get an error if that isn't the case. Here, you have int elements[this->cap]

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Consider: struct A { A (int); A (const A &); }; struct B { A foo [2]; B (const A & x, const A & y) : foo {x, y} /* HERE IS THE PROBLEM */ {} }; I was expecting this to work since I'm using C++0x support in GCC4.3, which allegedly supports initialiser lists. No joy. I have a class A which has no default constructor. This is not negotiable. Assignment post-default is not an option. I am trying to create B which uses A. B::foo may not be std::vector. How can I initialise B::foo in B(...) , constructing its elements exactly once? At the moment,

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have two arrays that I want to loop in. I construct those properly and before going into for loop, I do echo them to be sure everything is ok with arrays. But when I run the script, it outputs an error: l<=: syntax error: operand expected (error token is "<=" I consulted the mighty Google and I understood it suffers from the lack of the second variable, but I mentioned earlier I do echo the values and everything seems to be OK. Here is the snippet.. #!/bin/bash k=0 #this loop is just for being sure array is loaded while [[ $k -le ${#hitEnd

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: My understanding is that observing for '@each' means that I'm observing any change to any property in an array, but it doesn't seem to work. For example: App.ArrayProxy = Ember.ArrayProxy.extend({ i: 0, foo: function(){ console.log('foo called'); return ++this.i; }.property('content.@each') }); I've also tried .property('@each') instead of .property(' content.@each ') with equally disappointing results. Here is a jsbin that demonstrates: http://jsbin.com/hagar/5/edit In the demo, changing the array list itself (by clicking the 'Remove Last'

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am using jQuery to build an array of images from a php array. I want to loop through these images, preloading them while displaying a little loading gif until all of the images are loaded. At the moment, I have tried many methods of doing so and the rest of the page always seems to carry on loading and so the images are being preloaded, but not before the page loads the rest of the content. Here is what I have: <script type="text/javascript"> // Get list of images and build array + set vars var imgArray = new Array; var imgCount = <?php

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'd like some help please. I have created dynamic a menu navbar that displays the menu items accoridning to the order that I've set them. I'm using this nestedsortable plugin, to order my menu items, but currently my menu has only 2 levels, so basicly it goes like this: Item1 Item2 > Subitem2.1 > Subitem2.2 Item3 etc etc. What I'd like to do is make it with n-levels, so basicly something like this: Item1 Item2 > Subitem2.1 >> Subitem2.1.1 > Subitem2.2 Item3 etc etc. and each item can go n-level deep. The problem is that if I set a new order

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: If I have a variable inside a function (say, a large array), does it make sense to declare it both static and constexpr ? constexpr guarantees that the array is created at compile time, so would the static be useless? void f() { static constexpr int x [] = { // a few thousand elements }; // do something with the array } Is the static actually doing anything there in terms of generated code or semantics? 回答1: The short answer is that not only is static useful, it is pretty well always going to be desired. First, note that static and constexpr

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: What is the differece between: [[NSMutableArray alloc] init] and [NSMutableArray array] 回答1: Here in [NSMutableArray array] you don't have to release array it will be released automatically. & if you will write [NSMutableArray alloc] init] you will have to release array so [[NSMutableArray array] will be equivalent to [[[NSArray alloc] init] autorelease]; 回答2: The first remains in memory until you release it, the second lasts until the end of the run loop iteration. 回答3: NSMutableArray no need to release memory and [NSMutableArray alloc]