loops

问题 This is likely a quick fix! I am trying to place the ith position of my vector into my data frame column name. I am trying to use paste0 to enter the ith number. sma <- 2:20 > sma [1] 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 # Place i number from sma vector to data frame column name spx.sma <- df$close.sma.paste0("n", sma[i]) Column name should read: "close.sma.n2" If I print paste0("n", sma[i]) I obtain: > paste0("n", sma[i]) [1] "n2" So really if i paste this into my data frame

问题 How can I use one command line to provide a list of all files between a certain size and then format the file with name, md5 has and the file size. The example output should be file1.*** MD5 value size file2.*** MD5 value size etc. Ive tried the following but it displays the md5 on a separate line find 'directory' -size +30000c -size -50000c | while read filename do ls -l "$filename" | awk '{print $9 "\t" $5}' md5sum "$filename" | awk '{print $1}' done It outputs the follow with the MD5 on a

问题 How can I use one command line to provide a list of all files between a certain size and then format the file with name, md5 has and the file size. The example output should be file1.*** MD5 value size file2.*** MD5 value size etc. Ive tried the following but it displays the md5 on a separate line find 'directory' -size +30000c -size -50000c | while read filename do ls -l "$filename" | awk '{print $9 "\t" $5}' md5sum "$filename" | awk '{print $1}' done It outputs the follow with the MD5 on a

问题 I'm trying to push objects into an array to end up with an object array like this: [ {"recipient_name":"John D", "phone_number":"123456"}, {"recipient_name":"Doe J", "phone_number":"654321"}, {"recipient_name":"Jon Do", "phone_number":"112233"}, ] So I'm looping over a larger array to acquire the names and phone numbers and pushing them as an object to an array like this: $myLargerArray = pg_fetch_all($messageQuery); // This is my larger array $size = count($myLargerArray); for( $j = 0; $j <

问题 I'm just curious: Is there a difference on speed and performance between this two loops implementation? Assume that size() method returns the length of the array,collection, or object that handles a group of elements (actually it's from XOM api). Implementation 1: int size = someArray.size(); for (int i = 0; i < size; i++) { // do stuff here } Implementation 2: for (int i = 0; i < someArray.size(); i++) { // do stuff here } 回答1: From a performance point of view, there is little difference.

问题 Something like this seemed pretty logical to me but caused phantom to wtfcrash (That's what it's called in the log but doesn't give helpful info)... do { casper.then(function() { var targetFound = false; links = this.evaluate(getLinks); var searchResultsAr = []; for (var link in links) { searchResultsAr.push(links[link].replace('/url?q=', '').split('&sa=U')[0]); } for (var result in searchResultsAr) { if (searchResultsAr[result] == target) { targetFound = true; casper.echo(targetFound); break

问题 I am new to phpmysqli. Here is what I have and what am trying to achieve: I will update this based on the recommendations; Database sample data I want to display the data on one page with separate tables for each student based on their sid. This is what I have tried so far; <?php include_once 'dbcon.php'; $results = $MySQLiconn->query('SELECT * FROM activitybook'); $students = []; foreach ( $results->fetch_array() as $activity ) { $students[$activity['sid']][] = $activity; } foreach($students

问题 I am new to phpmysqli. Here is what I have and what am trying to achieve: I will update this based on the recommendations; Database sample data I want to display the data on one page with separate tables for each student based on their sid. This is what I have tried so far; <?php include_once 'dbcon.php'; $results = $MySQLiconn->query('SELECT * FROM activitybook'); $students = []; foreach ( $results->fetch_array() as $activity ) { $students[$activity['sid']][] = $activity; } foreach($students

问题 I have a large csv that I want to parse and insert into my database. I have this PHP: $target = '../uploads/'.$f; $handle = fopen($target, "r"); $data = fgetcsv($handle, 0, ","); $rows = array(); while ($data !== FALSE) { $rows[] = $data; } fclose($handle); if (count($rows)) { foreach ($rows as $key => $value) { echo $value; } } Every time I try to run my script I get this error: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 35 bytes) Any ideas how to do

问题 I have a large csv that I want to parse and insert into my database. I have this PHP: $target = '../uploads/'.$f; $handle = fopen($target, "r"); $data = fgetcsv($handle, 0, ","); $rows = array(); while ($data !== FALSE) { $rows[] = $data; } fclose($handle); if (count($rows)) { foreach ($rows as $key => $value) { echo $value; } } Every time I try to run my script I get this error: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 35 bytes) Any ideas how to do