range | 易学教程

How can I pattern match on a range in Scala?

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问题 In Ruby I can write this: case n when 0...5 then "less than five" when 5...10 then "less than ten" else "a lot" end How do I do this in Scala? Edit: preferably I'd like to do it more elegantly than using if . 回答1: Inside pattern match it can be expressed with guards: n match { case it if 0 until 5 contains it => "less than five" case it if 5 until 10 contains it => "less than ten" case _ => "a lot" } 回答2: class Contains(r: Range) { def unapply(i: Int): Boolean = r contains i } val C1 = new

Set textarea selection in Internet Explorer

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问题 I'm looking for a way to set a selection in a textarea in Internet Explorer. In other browsers, this works just fine: textarea.selectionStart = start; textarea.selectionEnd = end; In IE, I assume I have to use createRange and adjust the selection somehow, but I cannot figure out how. Extra bonus points for a link to a proper documentation about createRange and associated methods, MSDN isn't helping out much. 回答1: This works for me: <textarea id="lol">

How to check if an integer is within a range of numbers in PHP?

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问题 How can I check if a given number is within a range of numbers? 回答1: The expression: ($min <= $value) && ($value <= $max) will be true if $value is between $min and $max , inclusively See the PHP docs for more on comparison operators 回答2: You can use filter_var filter_var( $yourInteger, FILTER_VALIDATE_INT, array( 'options' => array( 'min_range' => $min, 'max_range' => $max ) ) ); This will also allow you to specify whether you want to allow octal and hex notation of integers. Note that the

MySQL display all date in between range [duplicate]

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问题 This question already has answers here : generate days from date range (29 answers) Closed 6 years ago . I want to display all dates between a from and to dates from MySQL. For example the data from schedule table that has from and to fields are: from date is 2013-3-13 , and to date is 2013-3-20 , my desired result is: 2013-3-13 2013-3-14 2013-3-15 2013-3-16 2013-3-17 2013-3-18 2013-3-19 2013-3-20 How can I achieve this using MySQL query only (without having to use stored procedure 'cause I'm

Winform文件下载之断点续传

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 在本系列的前两篇文章中，分别向大家介绍了用于完成下载任务的 WebClinet 和 WinINet 的基本用法和一些实用技巧。今天来为大家讲述下载过程中最常遇到的断点续传问题。首先明确一点，本文所说的断点续传特指 HTTP 协议中的断点续传，文章中讲述了实现断点续传的方法思路和关键代码，想了解更多细节的同学，请下载并查看本文附带的 demo。工作原理 http 协议中定义了一些请求/响应头，通过组合使用这些头信息，即可实现分批下载同一文件的目的。例如，在一次 http 请求中只请求文件中的一部分数据，然后将请求到的数据保存起来，下次只需请求剩余部分的数据，当全部数据都下载到本地后再完成数据的合并工作。 http 协议指出，可以通过 http 请求中的 Range 头来指定请求数据的范围。 Range 头的使用很简单，按照如下的格式使用即可： Range: bytes=500-999 上述意思为：只请求目标文件的第500至第999，这500个字节。举例说明，有一个1000 字节大小的文件需要下载，第一次请求时不指定 Range 头，表示下载整个文件；但在下载完第499个字节后，下载被中断了，那么在下一次请求剩余文件时，只需要下载第500个至第999个字节的数据即可。原理看上去很简单

Merge overlapping ranges into unique groups, in dataframe

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问题 I have a dataframe of n rows and 3 df <- data.frame(start=c(178,400,983,1932,33653), end=c(5025,5025, 5535, 6918, 38197), group=c(1,1,2,2,3)) df start end group 1 178 5025 1 2 400 5025 1 3 983 5535 2 4 1932 6918 2 5 33653 38197 3 I would like to make a new column df$group2 that re-classifies groups that overlap to be the same. For example, df$group[df$group==1] starts at 178 and ends at 5025. This overlaps with df$group[df$group==2] , which starts at 983 and ends at 6918. I would like to make

Generate N random numbers within a range with a constant sum

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问题 I want to generate N random numbers drawn from a specif distribution (e.g uniform random) between [a,b] which sum to a constant C. I have tried a couple of solutions I could think of myself, and some proposed on similar threads but most of them either work for a limited form of problem or I can't prove the outcome still follows the desired distribution. What I have tried: Generage N random numbers, divide all of them by the sum of them and multiply by the desired constant. This seems to work

Generate N random numbers within a range with a constant sum

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Create Chart from Array data and not range

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问题 is it possible to create a Chart (e.g. Double Y-Axis Line Chart) not from Ranges, but from Array data? If so, how? 回答1: Yes. You can assign arrays to the XValues and Values properties of a Series object on a chart. Example: Dim c As Chart Dim s As Series Dim myData As Variant Set c = ActiveChart ' Assumes a chart is currently active in Excel... Set s = c.SeriesCollection(1) myData = Array(9, 6, 7, 1) ' or whatever s.Values = myData 回答2: You can assign arrays to chart series in Excel 2007

Parsing HTTP_RANGE header in PHP

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问题 Is there an existing way to parse the HTTP_RANGE header correctly in PHP? Thought I'd ask here before re-inventing the wheel. I am currently using preg_match('/bytes=(\d+)-(\d+)/', $_SERVER['HTTP_RANGE'], $matches); to parse the header but that does not cover all possible values of the header so I am wondering if there is a function or library that can do this already? Thanks in advance. 回答1: Rather use regex to test it before sending a 416. Then just parse it by exploding on the comma , and