assign

问题 I'm trying to populate a 3d array from data stored in an Excel worksheet. I'm hoping I just don't know the syntax, but it may not be possible to 'batch' assign values to 3D arrays like you can with 2D arrays. Such as... Dim 2DArray() As Variant 2DArray = Range(A1:C10) This is so clean and efficient I was hoping for something equivalent, as opposed to using 3 nested for-next loops to populate the data one value at a time. For background this is to lookup/interpolate a gas compressibility

问题 It seems really inefficient that in PHP, when an array is assigned by value all of its internal elements are recursively copied to the new variable. Is this what really happens internally? 回答1: No, the internally array is not deep-copied on assignment. Consider the following snippet: $a = array(111, 222, 333); $b = $a; $b[0] = 999; If a picture is worth a thousand words, then here is what happens internally when arrays are assigned and then their array elements are modified: 来源： https:/

问题 I'm having trouble changing the contents of a variable holding a string. I'm probably thinking of this too literally compared to an int and not as an array. Maybe have to flush array first? Much thanks. // declare with maximum size expected +1 (for terminator 0) char myString1[20] = "Hello"; //declare and assign one line - OK myString1[20] = "Hello Longer"; // change contents - fails myString1[] = "Hello Longer"; // change contents - fails myString1 = "Hello Longer"; // change contents -

问题 I have a very simple question but I've stocked in it! I have a list as an output : as an example : lapply(1:40, function(x){ (1+x)}) output: [[1]] [1] 2 [[2]] [1] 3 [[3]] [1] 4 till [[40]] [1] 41 I wondered how can I assign each of the outputs of this list to a new variable by using a loop? something like this a<- [[2]]; b <- [[3]]; ... az <- [[40]] and so one. Thanks in advance, 回答1: Here is my solution, it requires that your output of lapply is stored with the name ll but it can be easily

问题 The following Tensorflow code works fine and v1 becomes [1., 1., 1.] v1 = tf.get_variable('v1', shape=[3], initializer=tf.zeros_initializer) v1 = v1 + 1 with tf.Session() as sess: sess.run(tf.global_variables_initializer()) print (v1.eval()) The following code segment also gives us the exactly the same result as the above. v1 becomes [1., 1., 1.] if we run sess.run(inc_v1) . v1 = tf.get_variable('v1', shape=[3], initializer=tf.zeros_initializer) inc_v1 = v1.assign(v1 + 1) with tf.Session() as

问题 Iam have a DBC file, which is a database file for a game, containing ingame usable spell data, like ID, SpellName, Category etc... Struct is something like this: [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1)] public struct SpellEntry { public uint ID; public uint Category; public float speed; [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8, ArraySubType = UnmanagedType.I4)] public int[] Reagent; public int EquippedItemClass; [MarshalAs(UnmanagedType.LPStr)] //

问题 I want to use a dynamic variable whose value will vary during the run time. eg char * aVar = "ABC"; char * bVar = "DEF"; char * cVar = "XYZ"; char *dVar = NULL; dVar = foo1(); print dVar; foo1 internally calls foo2 , which should return the variable names (like "aVar" , "bVar" or "cVar" ). foo1 should return the value of said variable as named according to foo2 's return value. to get the variable name we can use (non-standard) macro: ##define GET_VAR(varname) #varname; ... but how am I able

问题 I am writing a program to assist with a trivial part of my job that can be automated. My purpose here is to: Copy and paste a chunk of plain text into a Tkinter text widget Use that pasted chunk of text as the value of a variable so that the variable can have certain characters pulled and returned down the line. I have a functioning little bit of code. For example, here is my text widget and the lines of code I use to get and print its contents: textBox = Text(root) textBox.focus_set() def

问题 I have a MySQL Database Table containing products and prices. Though an html form I got the product name in a certain php file. For the operation in this file I want to do I also need the corresponding price. To me, the following looks clear enough to do it: $price = mysql_query("SELECT price FROM products WHERE product = '$product'"); However, its echo returns: Resource id #5 instead a value like like: 59.95 There seem to be other options like mysqli_fetch_assoc mysqli_fetch_array But I can

问题 I have a list of objects in R on which I perform different actions using lapply . However in the next step I would like to apply functions only to certain elements of the list. Therefore I would like to split the list into the original variables again. Is there a command in R for this? Is it even possible, or do I have to create new variables each time I want to do this? See the following example to make clear what I mean: # 3 vectors: test1 <- 1:3 test2 <- 2:6 test3 <- 8:9 # list l: l <-