syntax

问题 I was looking through some code and found 2 lines that perplexed me: add -0x4(%esi,%ebx,4),%eax cmp %eax,(%esi,%ebx,4) I am accustomed to the standard add src,dst and cmp x1,x2 and I'm not really sure what these lines are actually doing. I believe that it is compiled with GCC 回答1: That's using the Base + (Index * Scale) + Displacement addressing mode. At least, I think so. I'm not real familiar with the AT&T syntax. I think the Intel syntax would be: add eax,[esi + ebx*4 - 4] cmp [esi + ebx*4

问题 I'd like to generate a list of n_length consisting of randomly generated numbers within a defined range. What I'd like to know is whether I'm missing something built-in, something that would allow me to do this in the future in a more pythonic and cleaner way. Thanks for any thoughts. In [59]: from random import randrange In [60]: x_list = [0]*100 In [61]: rand_list = [randrange(700, 1500) for x in x_list] Basically, I don't like my x_list because I think it's kind of arbitrary, and I doubt

问题 I am using JSON within my javascript and I am trying to get a string value for the dot notation representation. For example AAA.BBB[0].CCC.DDD[5].EEE = 123 in JSON dot notation format. But I want to get the value AAA.BBB[0].CCC.DDD[5].EEE as a String so I can save it for later use to allow me to modify my JSON code directly. Is there a method in Javascript or jQuery that can return a string value representation? *EDIT I am converting JSON data into a list structure, and I want to save the AAA

问题 I'm trying to print the addresses of the elments of an array in decimal instead of hexa but it doesn't work. Below is the code and output example. #include <iostream> #include <iomanip> using namespace std; void printarrandptr(int arr[], int size); const int LEN = 5; void main(){ int arr[LEN] = { 15, 3, 14, 11, 14 }; int *p[LEN]; printarrandptr((int*)arr, LEN); } void printarrandptr(int arr[], int size){ int i; for (i = 0; i < size; i++) cout << setw(9) << &arr[i] << setw(4) << arr[i] << endl

问题 I have a CUDA (C++) code that uses function templates exclusively for performance reasons, so that the function will do only what it needs to do and not constantly be loading and reading booleans to check wether it needs to do stuff or not. All template arguments are booleans. At launch of the kernel the CPU checks the values of the booleans and launches the appropriate, I believe it's called, "instantiation" of the kernel template. I understand this gives exponential code size growth but my

问题 I have a CUDA (C++) code that uses function templates exclusively for performance reasons, so that the function will do only what it needs to do and not constantly be loading and reading booleans to check wether it needs to do stuff or not. All template arguments are booleans. At launch of the kernel the CPU checks the values of the booleans and launches the appropriate, I believe it's called, "instantiation" of the kernel template. I understand this gives exponential code size growth but my

问题 What does the comma in the declaration below mean? Does it define two variables at once? resp, content = client.request(request_token_url, "GET") 回答1: It creates a tuple. In this case, the tuple is of two variables, which get assigned the result from request() . request() returns a tuple, which is then automatically unpacked into the left-hand tuple during assignment. If you had just result = client.request(request_token_url, "GET") that would assign the tuple directly to result. Then you

问题 I've seen some code that uses the keyword this in the function parameter declaration. For example: public static Object SomeMethod( this Object blah, bool blahblah) What does the word this mean in that context? 回答1: It means SomeMethod() is an extension method to the Object class. After defining it you can call this method on any Object instances (despite it being declared static ), like so: object o = new Object(); bool someBool = true; // Some other code... object p = o.SomeMethod(someBool)

问题 As an experiment, I tried to extend an int -array like this: public class IntArrayExtension extends int[]{ // additional fields and methods. } to add some methods related to sorting, swapping, sub-array building etc. in the class itself. But I got this error while compiling: IntArrayExtension.java:1: unexpected type found : int[] required: class public class IntArrayExtension extends int[]{ ^ 1 error I am curious to know: why Java does not allow to extend an array? 回答1: Extending a

问题 I've used the switch statement the following way: switch (ch){ case 'P' || 'p': goto balance; break; case 'r' || 'R': goto menu; break; default: cout<<"\t\tInvalid Choice!!"<<endl; system ("\t\tpause"); system ("cls"); goto menu; break; } But it seems there's something wrong with the following syntax: case 'r' || 'R' Compiler complains about "duplicate case value". What's wrong with my code? 回答1: Change it to case 'P': case 'p': goto balance; break; Using goto is usually not a good idea. In