variables

问题 I was reading 'Pointers on C' by Kenneth Reek and saw this line: A structure variable is a scalar, so you can perform the same kinds of operations with it that you can with other scalars. So what does it mean? I found a similar question on SO but it was related to some other language (I guess SQL) Thank you. 回答1: Section 6.2.5 of the C11 standard explains: Arithmetic types and pointer types are collectively called scalar types. Array and structure types are collectively called aggregate types

问题 I was reading 'Pointers on C' by Kenneth Reek and saw this line: A structure variable is a scalar, so you can perform the same kinds of operations with it that you can with other scalars. So what does it mean? I found a similar question on SO but it was related to some other language (I guess SQL) Thank you. 回答1: Section 6.2.5 of the C11 standard explains: Arithmetic types and pointer types are collectively called scalar types. Array and structure types are collectively called aggregate types

问题 I've been having trouble figuring out how to get a variable to work Selenium. This post seems to have helped (Variable not working inside parenthesis) but I still can't get it to work. When I used the actual value it works. In this case AL-Alabama. I created a variable called state so that I can just call that in my function. I have 13 states to run through. driver.find_element_by_xpath("//option[@value='AL-Alabama']").click() This one uses the state variable and in looking at error message

问题 I'm running a PHP script and continue to receive errors like: Notice: Undefined variable: my_variable_name in C:\wamp\www\mypath\index.php on line 10 Notice: Undefined index: my_index C:\wamp\www\mypath\index.php on line 11 Line 10 and 11 looks like this: echo "My variable value is: " . $my_variable_name; echo "My index value is: " . $my_array["my_index"]; What is the meaning of these error messages? Why do they appear all of a sudden? I used to use this script for years and I've never had

问题 I am trying to print the variable whenever the variable $PrinterStatus is returning any data but the correct data is not coming with If else logic. $CurrentTime = Get-Date $PrinterStatus= Get-Printer -ComputerName "TGHYT-6578UT" | Foreach-Object { $Printer = $_ $Printer | Get-Printjob | Where-Object {$_.jobstatus -ne "Normal" -and $_.SubmittedTime -le $CurrentTime.AddHours(-1) } | Select-Object @{name="Printer Name";expression={$_.printerName}}, @{name="Submitted Time";expression={$_

问题 I am writing a class where I need to check whether the instance variables are of a certain type. I noticed that there is a lot of repeating code. Is there a better way to do similar checks on the instance variables? Or is this the right way to do it? class Variable(): __type = 'Variable' def __init__(self, id = None, updateable = True, name = 'Variable', value=None): if id is not None: self.id = id if value is not None: self.value = value self.updateable = updateable self.name = name

问题 I am writing a class where I need to check whether the instance variables are of a certain type. I noticed that there is a lot of repeating code. Is there a better way to do similar checks on the instance variables? Or is this the right way to do it? class Variable(): __type = 'Variable' def __init__(self, id = None, updateable = True, name = 'Variable', value=None): if id is not None: self.id = id if value is not None: self.value = value self.updateable = updateable self.name = name

问题 char x [1000]; x = 'hello'; What would I use to clear the contents of x ? I'm not able to re-initialise it, use strcpy(x, '/0') or free() . 回答1: You cannot assign anything to an array, which your variable x is. So therefore anything that starts with x = is wrong. Secondly 'hello' is not a string, it is a multicharacter literal which is of type int , so this doesn’t make sense either. A string literal is enclosed by " while character (or multicharacter) literals are enclosed by ' . So if you

问题 I'm writing a bash script which creates a user account. The username and password hash are pulled from a file based on certain criteria. The password hash naturally contains '$' delimiting the hash's fields (eg. $1${SALT}$...). The issue is that the -p option for useradd requires single quotes around the password hash in order to prevent the '$' fields from being interpolated as variables. When passing a variable, in order to properly interpolate it, the quotes need to be double. Single

问题 I am creating a program for a project that will help me learn visual basic. But when I work out how much a certain material is worth with dimensions. It come out with more than two decimal places. I know how to use math.floor function but it doesn't round to 2 decimal places. Does anyone know what function I should use to round to two decimal places? 回答1: The Decimal.Round method will do the trick for you. You can specify the number of decimal places. 回答2: You can use; Math.Round([DECIMAL], 2