evaluation

evaluation of assignment in php

由 余生长醉 提交于 2019-12-08 14:56:25
问题 I have a kind of 'basics' question about php. In the example code for fgets, it has this snippet as an example of reading through a file's contents: while (($buffer = fgets($handle, 4096)) !== false) { echo $buffer; } How is it that the statement ($buffer = fgets($handle, 4096)) can have a value? Is it a kind of assignment+evaluation of $buffer ? I mean, how does it get its value? Is there a name for this? I notice its using strict comparison, so do all assignments evaluate to a boolean true

force-evaluate an object being passed as an argument to a function

由 筅森魡賤 提交于 2019-12-08 11:29:42
问题 I would like to pass the value of an object as an argument to a function. # This is my object anObject <- "an_unkown_string" # I would like to do the equivalent of: someFunc("an_unkown_string") # .. by somehow calling on the object containing the string someFunc( ??? (anObject) ) For example, with the sample function below (based on save() ): someFunc <- function(...) { names <- as.character(substitute(list(...)))[-1L] return(names) } # Ideally, the output would be: someFunc( ??? (anObject) )

Why do we have to reverse the string when converting from infix to prefix

由 梦想的初衷 提交于 2019-12-08 08:12:39
问题 In the first step itself of converting an infix to prefix can someone explain in simple terms why should we reverse the string? Is there any alternative method to convert? 回答1: Yes, you are absolutely right that if you have to convert infix to prefix then you have to scan the string from right to left. Why not from left to right? If you scan from left to right then you will require future knowledge of operators in the string. Example 1 : Infix : 2+3 Prefix : +23 Now, when you convert it from

JFreeChart Boxplot Outlier and Farout appearance

由 被刻印的时光 ゝ 提交于 2019-12-08 07:44:54
问题 I am using JFreeChart with Java to evaluate experimental results using the boxplot chart. I want to change the color and shape of the outliers and the farout entries. This is how my plots currently look like when I use the normal BoxAndWhiskerRenderer: I set up the renderer like this: BoxAndWhiskerRenderer renderer = new BoxAndWhiskerRenderer(); renderer.setFillBox(true); renderer.setSeriesPaint(0, Color.DARK_GRAY); renderer.setSeriesPaint(1, Color.LIGHT_GRAY); renderer.setSeriesOutlinePaint

In Kotlin, is it possible to use a variable to call a method or property?

由 烈酒焚心 提交于 2019-12-08 07:04:26
问题 Simply put, I have a variable that tells me which property I need to modify on an object, but cannot call that property AS the variable. data class MyDataClass(var one: String, var two: Int) fun doSomething() { myData = MyDataClass("first", 2) val propertyImInterestedIn = "one" myData.{propertyImInterestedIn} = "second" // How do I do this? assertEquals("second", myData.one) } 回答1: You can either do it at compile time if You can directly reference the fields, or at runtime but you will lose

Evaluation of a reference expression

由 ＊爱你＆永不变心＊ 提交于 2019-12-08 00:23:28
问题 As per @Potatoswatter's suggestion, I have created a new discussion. Reference is this response from @Potatoswatter Given the code snippet, int i = 3, &j = i; j = ++ i; The comment which I seek clarity on, is this. (which seems to be an important missing piece in my understanding of the unsequenced evaluation a.k.a sequence point): @Chubsdad: Even though it's an alias, its glvalue evaluation does not require a glvalue evaluation of i. Generally speaking, evaluating a reference does not

Defined argument evaluation order leads to sub-optimal code?

由 天涯浪子 提交于 2019-12-07 06:19:34
问题 It is a known fact that argument evaluation order in c and c++ are not defined: for example: foo(a(),b()) In the above call it is up to the implementation of the compiler to decide which order of evaluation to pick and hence forth which function to execute first. Lately one of my friends asked why is the order of evaluation unspecified in C or C++. When I googled it, I came to know that specifying an evaluation order would lead to sub-optimal code generation. But how is it so? Why would a

In Kotlin, is it possible to use a variable to call a method or property?

由 风格不统一 提交于 2019-12-07 03:34:17
Simply put, I have a variable that tells me which property I need to modify on an object, but cannot call that property AS the variable. data class MyDataClass(var one: String, var two: Int) fun doSomething() { myData = MyDataClass("first", 2) val propertyImInterestedIn = "one" myData.{propertyImInterestedIn} = "second" // How do I do this? assertEquals("second", myData.one) } You can either do it at compile time if You can directly reference the fields, or at runtime but you will lose compile-time safety: // by referencing KProperty directly (compile-time safety, does not require kotlin

JFreeChart Boxplot Outlier and Farout appearance

由 ∥☆過路亽．° 提交于 2019-12-06 21:15:30
I am using JFreeChart with Java to evaluate experimental results using the boxplot chart. I want to change the color and shape of the outliers and the farout entries. This is how my plots currently look like when I use the normal BoxAndWhiskerRenderer: I set up the renderer like this: BoxAndWhiskerRenderer renderer = new BoxAndWhiskerRenderer(); renderer.setFillBox(true); renderer.setSeriesPaint(0, Color.DARK_GRAY); renderer.setSeriesPaint(1, Color.LIGHT_GRAY); renderer.setSeriesOutlinePaint(0, Color.BLACK); renderer.setSeriesOutlinePaint(1, Color.BLACK); renderer.setUseOutlinePaintForWhiskers

Condition evaluation process in Java [duplicate]

由 一曲冷凌霜 提交于 2019-12-06 17:54:15
问题 This question already has answers here : short-circuiting behavior of conditional OR operator(||) (3 answers) Closed 6 years ago . Lets say I have the following condition: if ( myList == null || myList.isEmpty() || xomeX == someY ) What is the order of the evaluation of these conditions? Left or right, right to left or random each time? If the first one passes, then the others are ignored? 回答1: It should be always be left to right except the assignment operator = . You are using short circuit
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