require | 易学教程

What is the difference between include and require in Ruby?

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问题 My question is similar to \"What is the difference between include and extend in Ruby?\". What\'s the difference between require and include in Ruby? If I just want to use the methods from a module in my class, should I require it or include it? 回答1: What's the difference between "include" and "require" in Ruby? Answer: The include and require methods do very different things. The require method does what include does in most other programming languages: run another file. It also tracks what

Golang modules 初探

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今天天色刚刚亮起，起床看到golang 1.11正式发版了，有着两个重要的特性：modules和WebAssembly。本博文只要说的是modules，congJava转golang的同学肯定是对golang的包管理充满了无奈之情，我也曾在博客中介绍过 glide ，也介绍过 dep ，现在我们再一次升级介绍modules。什么是modules 现在都在说modules，那么它是什么？到文档看看 Modules, module versions, and more ： A module is a collection of related Go packages. Modules are the unit of source code interchange and versioning. The go command has direct support for working with modules, including recording and resolving dependencies on other modules. Modules replace the old GOPATH-based approach to specifying which source files are used in a given build. 翻译一下：

Nodejs cannot find installed module on Windows

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问题 I am learning nodejs at the moment on Windows. Several modules are installed globally with npm.cmd, and nodejs failed to find the installed modules. Take jade for example, npm install jade -g Jade is installed in directory \"C:\\Program Files (x86)\\nodejs\\node_modules\" , but the following code will fail with a \"Cannot find module \'jade\'\" error, var jade = require(\'jade\'); However, the code will run successfully when jade is locally installed (without -g option in npm). I don\'t want

Difference between “include” and “require” in php

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Is there any difference between them? Is using them a matter of preference? Does using one over the other produce any advantages? Which is better for security? Steven You find the differences explained in the detailed PHP manual on the page of require : require is identical to include except upon failure it will also produce a fatal E_COMPILE_ERROR level error. In other words, it will halt the script whereas include only emits a warning ( E_WARNING ) which allows the script to continue. See @efritz's answer for an example efritz require will throw a PHP Fatal Error if the file cannot be loaded

What is the difference between require_relative and require in Ruby?

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问题 What is the difference between require_relative and require in Ruby? 回答1: Just look at the docs: require_relative complements the builtin method require by allowing you to load a file that is relative to the file containing the require_relative statement. For example, if you have unit test classes in the "test" directory, and data for them under the test "test/data" directory, then you might use a line like this in a test case: require_relative "data/customer_data_1" 回答2: require_relative is

How can I use jQuery in Greasemonkey scripts in Google Chrome?

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问题 As some of you may know, Google Chrome has put some severe limitation on Greasemonkey scripts. Chromium does not support @require , @resource , unsafeWindow , GM_registerMenuCommand , GM_setValue , or GM_getValue . Without require, I can\'t find a way to include the jQuery library in Greasemonkey script under Google Chrome. Does anybody have some advice in this matter? 回答1: From "User Script Tip: Using jQuery - Erik Vold's Blog" // ==UserScript== // @name jQuery For Chrome (A Cross Browser

智能合约编程语言-solidity快速入门（下）

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上一篇：智能合约编程语言-solidity快速入门（上） solidity区块及交易属性在介绍区块及交易属性之前，我们需要先知道solidity中自带了一些全局变量和函数，这些变量和函数可以认为是solidity提供的API，这些 API 主要表现为Solidity 内置的特殊的变量及函数，它们存在于全局命名空间里，主要分为以下几类：有关区块和交易的属性 ABI编码函数有关错误处理有关数学及加密功能有关地址和合约我们在编写智能合约的时候就可以通过这些API来获取区块和交易的属性（Block And Transaction Properties），简单来说这些API主要用来提供一些区块链当前的信息，下表列出常用的一些API： API 描述 blockhash(uint blockNumber) returns (bytes32) 返回给定区块号的哈希值，只支持最近256个区块，且不包含当前区块 block.coinbase (address) 获取当前块矿工的地址 block.difficulty (uint) 获取当前块的难度 block.gaslimit (uint) 获取当前块的gaslimit block.number (uint) 获取当前区块的块号 block.timestamp (uint) 获取当前块的Unix时间戳（从1970/1/1 00:00:00

Difference between require, include, require_once and include_once?

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问题 In PHP: When should I use require vs. include ? When should I use require_once vs. include_once ? 回答1: There are require and include_once as well. So your question should be... When should I use require vs. include ? When should I use require_once vs. require The answer to 1 is described here. The require() function is identical to include(), except that it handles errors differently. If an error occurs, the include() function generates a warning, but the script will continue execution. The

PHP - Failed to open stream : No such file or directory

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问题 In PHP scripts, whether calling include() , require() , fopen() , or their derivatives such as include_once , require_once , or even, move_uploaded_file() , one often runs into an error or warning: Failed to open stream : No such file or directory. What is a good process to quickly find the root cause of the problem? 回答1: There are many reasons why one might run into this error and thus a good checklist of what to check first helps considerably. Let's consider that we are troubleshooting the