concatenation

问题 I want to concatenate one element of a multidimensional array with some strings. <? $string1 = 'dog'; $string2 = array ( 'farm' => array('big'=>'cow', 'small'=>'duck'), 'jungle' => array('big'=>'bear', 'small'=>'fox') ); $string3 = 'cat'; $type = 'farm'; $size = 'big'; $string = "$string1 $string2[$type][$size] $string3"; echo($string); ?> By using this syntax for $string, I get: dog Array[big] cat I would like not to use the alternate syntax $string = $string1 . ' ' . $string2[$type][$size]

问题 Is there a way to use the arg 2 value of table.concat to represent the current table index? eg: t = {} t[1] = "a" t[2] = "b" t[3] = "c" X = table.concat(t,"\n") desired output of table concat (X): "1 a\n2 b\n3 c\n" 回答1: Simple answer : no. table.concat is something really basic, and really fast. So you should do it in a loop anyhow. If you want to avoid excessive string concatenation you can do: function concatIndexed(tab,template) template = template or '%d %s\n' local tt = {} for k,v in

问题 I was up coding at 3 AM last night, and I wake up today and find this in a source file: (curse words redacted) void append_this_stuff(char *stuff_to_append_to[], char **stuff_to_append, int position) { char the_actual_stuff[] = *(stuff_to_append_to); char *screw_me = *(stuff_to_append); int someNumber = strlen(screw_me); int j = 0; for (int i = position; i < (someNumber + position - 1); i++) { the_actual_stuff[i] = (screw_me + j); j++; } stuff_to_append_to = &the_actual_stuff; } When I try to

问题 This question already has answers here : how to concatenate more than two columns in plsql developer? [duplicate] (2 answers) Closed last year . it does not runing,please show me where I have a mistake? SELECT CONCAT(FIRST_NAME,',',LAST_NAME) as full_name FROM EMPLOYEES; 回答1: Use ANSI SQL's || instead to concat: SELECT FIRST_NAME || ',' || LAST_NAME as full_name FROM EMPLOYEES; ( CONCAT() function takes two arguments only.) 回答2: Concat only expects two Parameter, so you have to use nested

问题 I have taken a principles of programming class and have been given a Perl expression that concatenates a string number to an int number and then adds another number to it and it evaluates fine. i.e. ("4" . 3) + 7 == 50 . I'm trying to understand why Perl does this and what concerns it may bring up. I'm having a hard time grasping many of the concepts of the class and am trying to get explanations from different sources apart from my horrible teacher and equally horrible notes. Can the concept

问题 I need to merge strings together to create one string. For example the strings for "hello" that need to be combined are: [H----], [-E---], [--LL-], and [----O] This is the current code I have to make the letters appear in the first place. display_string = "[" + "".join([x if x == letter else "-" for x in word]) + "]" How would I go about making strings such as [H----], [HE---], [HELL-], and finally [HELLO]? 回答1: I don't know whether this helps in the way you wanted, but this works. The

问题 NOTE: I initially thought my problem had to do with CONCAT , but since the exact error persisted even when I completely eliminated CONCAT from my query, I figured I should completely over-write of my original post. I'm trying to set a trigger, and keep getting a Syntax Error. When I tried this CREATE TRIGGER set_aka_name BEFORE INSERT ON sandbox_person FOR EACH ROW BEGIN IF (NEW.aka IS NULL) THEN SET NEW.aka = 'test value'; END IF; END ...I got this error: 1064 - You have an error in your SQL

问题 i try to create table through jquery now i successfully display table and data if (re.length > 0) { $("#services_schdulue").append $('#services_schdulue thead').append( "<tr><th>Conactenate</th><th>frequency</th><th>FDuration</th><th>FMileage</th><th>Lperformed</th><th>Nddatetime</th><th>Ndmileage</th><th>Rfrequ</th><th>Rduration</th><th>RMileage</th></tr>" ); for (var i = 0; i < re.length; i++) { if (re[i] !== null) { $('#services_schdulue tbody').append( '<tr><td>' + con + '</td><td>' + re

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 5 years ago . I have a question. I have been trying to search the internet for an answer, but couldn't find the answer I am looking for: Assignment : I need to loop through several files (specified by the user), extract a column of the csv-files and "glue" them together to finally calculate the mean across the

问题 I am currently working on a project that will use a thermister as a temperature sensor and displaying this information among other things onto a gui using the raspberry pi. However I am currently stuck on the Analog to digital conversion. Using the sample code from the waveshare ad board I am using I manage to get the voltage to display, however I then need to use this vout in my voltage divider equation to get the resistance of my thermister and I can't figure out how to actually use the 32