option

jQuery获取Select选择的Text和Value: 语法解释： 1. $("#select_id").change(function(){//code...}); //为Select添加事件，当选择其中一项时触发 2. var checkText=$("#select_id").find("option:selected").text(); //获取Select选择的Text 3. var checkValue=$("#select_id").val(); //获取Select选择的Value 4. var checkIndex=$("#select_id ").get(0).selectedIndex; //获取Select选择的索引值 5. var maxIndex=$("#select_id option:last").attr("index"); //获取Select最大的索引值 jQuery设置Select选择的 Text和Value: 语法解释： 1. $("#select_id ").get(0).selectedIndex=1; //设置Select索引值为1的项选中 2. $("#select_id ").val(4); // 设置Select的Value值为4的项选中 3. $("#select_id option[text='jQuery']")

After using F# option type for a while, I realize that it could be used for handling exceptional cases. I can use either option or Exception in the following examples: The find functions from List/Array/Seq modules raise KeyNotFoundException in uncommon cases, while corresponding tryFind counterparts return None in those situations. When I do backtracking (in solving N-queens, Sudoku, etc), whenever a branch has no solution, I can either raise an exception and catch it later or return None to match that value to backtrack. Those cases occur quite often until we find a solution. My impression

Option(选项)类型用来表示一个值是可选的（有值或无值)。 ¶ 如果存在， Option[T] 就是 Some[T] ，如果不存在， Option[T] 就是对象 None myMap 一个是一个 Key -Value 的类型，但他的 get() 返回的是 Option 的类别 1. object Test { def main(args: Array[String]) { val sites = Map("runoob" -> "www.runoob.com", "google" -> "www.google.com") println("runoob："+sites.get("runoob")) println("baidu:"+sites.get("baidu")) }} Test.main(Array()) runoob：Some(www.runoob.com) baidu:None defined object Test 　　 2. 模式匹配 object Test { def main(args: Array[String]) { val sites = Map("runoob" -> "www.runoob.com", "google" -> "www.google.com") println("runoob:"+show(sites.get("runoob"))

I am looking for a way to get the value of an F# option or use a default value if it is None. This seems so common I can't believe something predefined doesn't exist. Here is how I do it right now: // val getOptionValue : Lazy<'a> -> Option<'a> -> 'a let getOptionValue (defaultValue : Lazy<_>) = function Some value -> value | None -> defaultValue.Force () I am (sort of) looking for the F# equivalent of the C# ?? operator: string test = GetString() ?? "This will be used if the result of GetString() is null."; No function in the Option module does what I think is a pretty basic task. What am I

Is there an option (maybe) wokflow (monad) in the standrd F# library? I've found a dozen of hand-made implementations ( 1 , 2 ) of this workflow, but I don't really want to introduce non-standard and not very trusted code into my project. And all imaginable queries to google and msdn gave me no clue where to find it. There's no Maybe monad in the standard F# library. You may want to look at FSharpx , a F# extension written by highly-qualified members of F# community, which has quite a number of useful monads. kvb There's no standard computation builder for options, but if you don't need things

I have a list of areas (1000+) and i was wondering if there was a way i can do this easier with code instead of repeating each value. <select> <option value="apple" <?php if ($user_data["$area"] == apple){echo 'selected';} ?>>Apple </option> <option value="lemon" <?php if ($user_data["$area"] == lemon){echo 'selected';} ?>>Lemon </option> <option value="orange" <?php if ($user_data["$area"] == orange){echo 'selected';} ?>>Orange </option> <option value="banana" <?php if ($user_data["$area"] == banana){echo 'selected';} ?>>Banana </option> </select> I.E. have the same piece of php code for each

使用python+selenium驱动chrome做自动化测试是一个很常见的场景，以前使用chrome时页面头部出现了一个小黄条报错提示“您使用的是不受支持的命令行标记:--ignore-certificate-errors。稳定性和安全性会有所下降”，可以通过设置chrome的option属性解决。 问题重现 使用python+selenium驱动chrome，页面出现小黄条报错“您使用的是不受支持的命令行标记:--ignore-certificate-errors。稳定性和安全性会有所下降” # -*- coding=UTF-8 -*- from selenium import webdriver import time import sys browser = webdriver.Chrome() browser.get("http://my.oschina.net/rasine") print "the page is opend!" 问题解决 使用option参数，该问题可以解决 options = webdriver.ChromeOptions() options.add_experimental_option("excludeSwitches", ["ignore-certificate-errors"]) browser = webdriver.Chrome

1 最直接的方式 scala> val jdbcDF = spark.read.format("jdbc") .option("url", "jdbc:mysql://hadoop1:3306/rdd")-------mysql 接口和库名 .option("dbtable", "rddtable")-----两张表名 .option("user", "root")----登陆的权限和用户名，照着写即可 .option("password", "cc123456")----登陆密码 .load() 结果： jdbcDF: org.apache.spark.sql.DataFrame = [id: int, name: string] 准备工作是你的有要连接mysql的库名，表名，并且要准备好数据。 2）我们连起来执行一下啊 scala> val jdbcDF = spark.read.format("jdbc").option("url", "jdbc:mysql://hadoop1:3306/rdd").option("dbtable", "rddtable").option("user", "root").option("password", "cc123456").load() jdbcDF: org.apache.spark.sql.DataFrame = [id: int