So I have declared a Session array and initialized it with zeroes. It's basically a multidimensional array. However, I'm thinking of converting it to a regular array because everytime I test whether a value exists or not using the in_array() function, it fails. It keeps adding existing values.
<?php
session_start();
$_SESSION['numbers'] = array(
array(0,0,0,0,0), //row1
array(0,0,0,0,0), //row2
array(0,0,0,0,0), //row3
array(0,0,0,0,0), //row4
array(0,0,0,0,0) //row5
);
?>
<?php
if (isset($_POST["num"]) && !empty($_POST["num"])){
$userInput = $_POST["num"];
for($r = 0; $r<sizeof($_SESSION['numbers']); $r++){
for($c = 0; $c<sizeof($_SESSION['numbers']); $c++){
$colVal = $_SESSION['numbers'][$r][$c];
insertInputAt($r,$c,$userInput);
}
}
}
function insertInputAt($row,$col,$input){
if(!in_array($input, $_SESSION['numbers'])){ //this fails
echo $input . "<br/>";
$_SESSION['numbers'][$row][$col] = $input;
}
}
?>
If I enter lets say 5, it inserts the input 5 to all rows and columns. I get 25 echos of value of 5 even if I put a !in_array() condition
I thought maybe if I parse the $_SESSION['numbers] as a regular array within the insertInputAt() method, the !in_array() condition might work accurately.
Thank you.
Modify your insertInputAt function to this:
function insertInputAt($row,$col,$input){
if(!in_array($input, $_SESSION['numbers'][$row])){ //this fails
echo $input . "<br/>";
$_SESSION['numbers'][$row][$col] = $input;
}
}
First of all, you do not need to initialize $_SESSION['numbers'].
<?php
session_start();
$userInput = $_POST["num"] = 1;
for($r=0;$r<count($_SESSION['numbers']);$r++){
$found = 0;
for($c=0;$c<count($_SESSION['numbers'][$r]);$c++){
if(($_SESSION['numbers'][$r][$c]==0)&&(myfunction($_SESSION['numbers'],$userInput)==0)){
$_SESSION['numbers'][$r][$c] = $userInput;unset($_POST['num']); $found=1;break;
}
}
if($found==1)break;
}
function myfunction($array,$value){
foreach($array as $q){
if(!in_array($value,$q)){
for($i=0;$i<count($q);$i++){
if($q[$i]==0) return false;
}
}
}
}
echo "<pre>";print_r($_SESSION['numbers']);
?>
Related
I'm trying to create a function to pick up words from a text file randomly, and no one here poblema. The problem arises when I try to verify if the user correctly inserts the words. Unfortunately, I always get a negative answer. From what I understood when called, the function can not save the contents into the variable that naturally remains empty.
<?php
function random_word() {
$dictionary = "dictionary.txt";
$word = file($dictionary);
$n = 0;
while ($n < 2) {
$n++;
$randomword = array_rand($word);
echo $word[$randomword];
}
}
$a = random_word();
echo "-----------------";
echo $a;
?>
If I try to check the $a variable it tells me that it is NULL. I'm sure the problem is the function but I know PHP shortly and I'm struggling to find the error.
You need to return something. Not sure if you want to return a string or an array but your code seems to be made for string.
<?php
function random_word() {
$dictionary = "dictionary.txt";
$word = file($dictionary);
$n = 0;
while ($n < 2) {
$n++;
$randomword = array_rand($word);
$returner .= $word[$randomword] . " ";
}
return trim($returner);
}
$a = random_word();
echo "-----------------";
echo $a;
?>
I have just written a program to check for the variable scopes in PHP. The code goes like this:
<?php
$value = 1;
function change_value(){
if(some_condition){
$value = 0;
$asset = 1;
}else{
$asset = 0;
}
return $asset;
}
echo $value;
change_value();
echo $value;
?>
Now, the output of the above program is 11.
How can I change the value of $value once it enters the function change_value() ?
Pass the parameter by reference:
<?php
$value = 1;
function change_value(&$value){
if(/* some_condition */){
$value = 0;
$asset = 1;
}else{
$asset = 0;
}
return $asset;
}
echo $value; // echoes 1
$asset = change_value($value);
echo $value; // echoes 0
echo $asset; // echoes 0 or 1 depending on /* some_condition */
?>
Please don't use global ... even if some suggest it.
It's bad. It let's the variable be accessable from all over the script and you will be very confused when you come upon the situation where you access $value in a different script you included and it acts different then...
What you're trying to do, goes against common principles, but.
$GLOBALS['value'] = 0;
Using this inside function will let you change that value, but I suggest you not to do this.
The way others have outlined, is far more right.
Recently I made a program to create 4 random numbers I want to put these numbers in an array but I did not echo the array's numbers :
my code is:
<?php
$numbers = array();
function rand_num_generator() {
return rand(1000,9999);
}
for($i=0;$i<4;$i++) {
$number[i] = rand_num_generator();
}
echo $number[2];
?>
Here i am not able to access array using their index values.
You missed the $ sign in front of the i inside $number[i] which must be used before a variable
$numbers = array();
function rand_num_generator() {
return rand(1000,9999);
}
for($i=0;$i<4;$i++) {
$number[$i] = rand_num_generator();
echo $number[$i].'<br>';
}
//print_r($number);to see the whole array
You only echo once: at echo $number[i];, $i is 4, hence you only display the last random number.
You could loop on your array to echo each.
Put your echo into loop. And you have some mistakes. Use that:
$numbers = array();
function rand_num_generator() {
return rand(1000,9999);
}
for($i=0;$i<4;$i++) {
$number[$i] = rand_num_generator();
echo $number[$i].'<br>';
}
To put something in an array I recommend to use array_push
<?php
$numbers = array();
function rand_num_generator() {
return rand(1000,9999);
}
for($i=0;$i<4;$i++) {
array_push($numbers, rand_num_generator());
}
print_r($numbers); //Or use 'echo $numbers[0] . " " . $numbers[1]' etc etc
?>
Here is my code :
<?php
$a=array(10,8,6,5);
$b=count($a);
for($i=0;$i<($b-1);$i++)
{
for($j=1;$j<($b);$j++)
{
if($a[$j]<$a[$i])
{
$temp = $a[$j];
$a[$j]=$a[$i];
$a[$i]=$temp;
}
}
}
I just want to know what's wrong in the above code ? because if i take 3 array values it works fine but for 4 its not working....can someone do the modification for the same code,and also please briefly explain why is it not working any issues with looping?I am not looking for different code.
You have mistakenly modified the bubble sort algorithm. Use standard one.
<?php
$a=array(10,8,6,5);
$b=count($a);
for($i=0;$i<($b);$i++) //Changes over here
{
for($j=0;$j<($b);$j++) //Changes over here
{
if($a[$j]>$a[$i]) //Changes over here
{
$temp = $a[$j];
$a[$j]=$a[$i];
$a[$i]=$temp;
}
}
}
Why are you manually sorting when you have sort?
$a = array(10,8,6,5);
sort($a);
var_dump($a);
Similarly, why are you using temporary variables when you have list?
list($a[$i],$a[$j]) = array($a[$j],$a[$i]);
try below code may be that will help.
<?php
function pr($array = array())
{
echo "<pre>";
print_r($array);
echo "</pre>";
}
$a = array(10,8,6,5);
$b = count($a);
for($i=0;$i <= ($b-1);$i++)
{
for($j=0; $j < ($b);$j++)
{
if($a[$j] < $a[$i])
{
$temp = $a[$j];
$a[$j]=$a[$i];
$a[$i]=$temp;
}
}
}
pr($temp);
pr($a);
?>
<?php
$a=array(8,6,5);
$b=count($a);
for($i=0;$i<($b);$i++)
{
for($j=0;$j<($b);$j++)
{
if($a[$j]<$a[$i])
{
$temp = $a[$j];
$a[$j]=$a[$i];
$a[$i]=$temp;
}
}
}
The inner loop doesn't need to be executed n times (where n=number of elements to be sorted). Every time the outer loop executes, one more element at the end (for ascending order) is in the correct position. So, inner loop should not check those elements.
<?php
$a=array(10,8,6,5);
$b=count($a);
for($i=0;$i<($b);$i++){
for($j=0;$j<($b-$i);$j++){ // this change will save time
if($a[$j]>$a[$i]){
$temp = $a[$j];
$a[$j]=$a[$i];
$a[$i]=$temp;
}
}
}
?>
I initialize a php array named $present, the purpose of this array is to hold the value of 1 if a name is present or zero if the name is absent. i have a name array of size 10. below is the code mentioned, but it is not working.
$present = Array();
for($i=0;$i<=10;$i++){
if(!isset($present[$name[$i]])) {
$present[$name] = 1;
}
else echo $present[$name[$i]];
}
i have also tried this :
$present = Array();
for($i=0;$i<=10;$i++){
if(empty($present[$name[$i]])) {
$present[$name] = 1;
}
else echo $present[$name[$i]];
}
please help thanks!
I think this may be what you are looking for. You're missing the $i when setting it to 1.
$present = array();
for($i=0;$i<=10;$i++){
if(!isset($present[$name[$i]])) {
$present[$name[$i]] = 1;
}
else echo $present[$name[$i]];
}
Should be:
$present = Array();
for($i=0;$i<10;$i++){
if(!isset($present[$name[$i]])) {
$present[$name[$i]] = 1;
}
else echo $present[$name[$i]];
}
I'm not sure exactly what you're trying to do here, but if you just want to keep track of whether a name is present or not, you could just make $present be an array of names, and then use in_array.
$present = array('John', 'Paul', 'George');
echo in_array('John', $present); # returns 1
echo in_array('MacArthur', $present); #returns 0