global-variables

问题 I am new to react, and I am trying to make a simple countdown app. but in react, I don't know how to give a global variable for all the functions can get assess to it. Please take a look at my code, is there anyway I can make the pause and the continue buttons work? In plain javascript I can set timer as a global variable and get access to it from another function, by that, I can call clearInterval on timer when I want, but in react I don't know how to call clearInterval for timer to pause

问题 This package uses two unique features of Oracle, REF_CURSOR and a package global variable. I would like to port the functionality from Oracle to Postgresql or MySQL. PACKAGE tox IS /*=======================*/ g_spool_key spool.key%TYPE := NULL; TYPE t_spool IS REF CURSOR RETURN spool%ROWTYPE; /*=======================*/ PROCEDURE begin_spool; /*=======================*/ PROCEDURE into_spool ( in_txt IN spool.txt%TYPE ); /*=======================*/ PROCEDURE reset_spool; /*====================

问题 I am creating some small programs with x86 assembly, and it's my first time using a low level language so I'm not used to it. In high level languages I rarely use global variables, but I've seen a lot of tutorials using global variables in assembly, so I'm not sure when to use global variables instead of local variables. By global variables I mean data created in the .bss and .data segments, and by local variables I mean data allocated on the stack of the current procedure, using the stack

问题 Like in R, I would like to set a random seed globally for the entire script/session, instead of having to call the random seed function every time I execute a function or run a model. I am aware that sci-kit learn uses the numpy RNG, but also could not find a way to set it globally. I have read several posts here on this topic, such as this one: Differences between numpy.random and random.random in Python It explains the difference between the two RNG classes, but not how to set it globally.

问题 I've got a variable called global_count that I would like to share between the shared library and the main part of the program (and ultimately other libs, but for now I've simplified the testcase). Given the declaration of global_count in globals.cpp: extern "C" { int* global_count; } We compile to create a global.o file: gcc -c global.cpp shared.cpp below will be used to create shared.so : #include <stdio.h> #include "global.h" extern "C" { void init_global_count(int* xp) { printf(

问题 I try to declare a global variable config : //general.h struct config_t { int num; }; extern struct config_t config; //The global variable Then I define config variable in general.c : //general.c #include "general.h" struct config_t config = { num = 5; }; But, when I try to use the global variable 'config' in my main function, I get the error: undefined reference to `config': Main program: //main.c #include "general.h" main() { config.num = 10; } Why is it? 回答1: This looks like a linker error

问题 I keep getting an unbound local error with the following code in python: xml=[] global currentTok currentTok=0 def demand(s): if tokenObjects[currentTok+1].category==s: currentTok+=1 return tokenObjects[currentTok] else: raise Exception("Incorrect type") def compileExpression(): xml.append("<expression>") xml.append(compileTerm(currentTok)) print currentTok while currentTok<len(tokenObjects) and tokenObjects[currentTok].symbol in op: xml.append(tokenObjects[currentTok].printTok()) currentTok+

问题 I'd believed that all global variables were accessible from the global object. So if I can access x (and x isn't bound locally), then window.x is the same value. However, in a webpage (on JSFiddle): window === this // true in Chrome and Firefox toString === window.toString // true in Chrome and Firefox But in the console: window === this // true in Chrome console and Firebug, false in Firefox web console toString === window.toString // false in Chrome, Firebug and Firefox web console Why is

问题 I'd believed that all global variables were accessible from the global object. So if I can access x (and x isn't bound locally), then window.x is the same value. However, in a webpage (on JSFiddle): window === this // true in Chrome and Firefox toString === window.toString // true in Chrome and Firefox But in the console: window === this // true in Chrome console and Firebug, false in Firefox web console toString === window.toString // false in Chrome, Firebug and Firefox web console Why is

问题 I'm trying to cancel a requestAnimationFrame loop, but I can't do it because each time requestAnimationFrame is called, a new timer ID is returned, but I only have access to the return value of the first call to requestAnimationFrame . Specifically, my code is like this, which I don't think is entirely uncommon: function animate(elem) { var step = function (timestamp) { //Do some stuff here. if (progressedTime < totalTime) { return requestAnimationFrame(step); //This return value seems