Get Highest number from array using for loop - php

I am trying to get highest number from array. But not getting it. I have to get highest number from the array using for loop.
<?php
$a =array(1, 44, 5, 6, 68, 9);
$res=$a[0];
for($i=0; $i<=count($a); $i++){
if($res>$a[$i]){
$res=$a[$i];
}
}
?>
I have to use for loop as i explained above. Wat is wrong with it?

This should work for you:
<?php
$a = array(1, 44, 5, 6, 68, 9);
$res = 0;
foreach($a as $v) {
if($res < $v)
$res = $v;
}
echo $res;
?>
Output:
68
In your example you just did 2 things wrong:
$a = array(1, 44, 5, 6, 68, 9);
$res = $a[0];
for($i = 0; $i <= count($a); $i++) {
//^ equal is too much gives you an offset!
if($res > $a[$i]){
//^ Wrong condition change it to <
$res=$a[$i];
}
}
EDIT:
With a for loop:
$a = array(1, 44, 5, 6, 68, 9);
$res = 0;
for($count = 0; $count < count($a); $count++) {
if($res < $a[$count])
$res = $a[$count];
}

What about:
<?php
$res = max(array(1,44,5,6,68,9));
(docs)

you should only remove the = from $i<=count so it should be
<?php $a =array(1,44,5,6,68,9);
$res=$a[0];
for($i=0;$i<count($a);$i++){
if($res<$a[$i]){
$res=$a[$i];
}
}
?>
the problem is that your loop goes after your arrays index and the condition is reversed.

The max() function will do what you need to do :
$res = max($a);
More details here.

Suggest using Ternary Operator
(Condition) ? (True Statement) : (False Statement);
<?php
$items = array(1, 44, 5, 6, 68, 9);
$max = 0;
foreach($items as $item) {
$max = ($max < $item)?$item:$max;
}
echo $max;
?>

Related

Find first number of each element in array and add them up without using strings

public function pom() {
$array = [25, 12, 5, 82, 15];
$result = 0;
for($i = 0; $i < count($array); $i++) {
$first = str_split($array[$i]);
if(is_numeric($first[0]))
$result += $first[0];
}
return $result;
}
it works like this but question says i cannot use strings . Does it mean i cannot use str_split ?
You can do that with substr array_map() and array_sum(),
<?php
$array = [25, 12, 5, 82, 15];
function sum_first_digit($array) {
$sum = array_sum(array_map(function ($a){return
substr($a,0,1);}, $array));
return $sum;
}
echo sum_first_digit($array);
?>
Output: 17
Extracting the first digit without the use of a string function means in my opinion only using calculations. Example:
$n = 781234;
$result = intdiv($n,pow(10,floor(log10($n)))); // 7

PHP count function

I have to count the numbers which is divisible by 5.
Here is my code,
$num = array(4, 25, 60, 7, 8);
foreach ($num as $numbers) {
if (($numbers % 5) == 0) {
echo count($numbers);
}
}
Output of above program is 11. But output should be 2. Please give me solution. Thanks in advance.
$nums = array(4, 25, 60, 7, 8);
To only count:
-Basic:
$count = 0;
foreach ($nums as $num) {
if ( $num % 5 == 0 ) $count++;
}
-Playing with types:
$count = 0;
foreach ($nums as $num) {
$count += !($num % 5);
}
$num % 5 returns an integer, !($num % 5) returns a boolean but since it is used as operand with the + operator, false and true act like 0 and 1.
-Functional version using array_reduce:
$count = array_reduce($nums, function($c, $i) { return $c + !($i % 5); });
To filter items, use the well named array_filter:
$result = array_filter($nums, function ($i) { return $i % 5 == 0; });
and count the number of items after if you want:
$count = count($result);
You can use this way also,
function divisibleby5($var){
return $var % 5 == 0;
}
$num = array(4, 25, 60, 7, 8);
echo count(array_filter($num,'divisibleby5');
I think you need to do something more like the following perhaps.
$num = array(4, 25, 60, 7, 8);
$numbers=array();
foreach( $num as $number ) {
if( $number % 5 == 0 ) $numbers[]=$number;
}
echo count( $numbers );
or alternatively using array_walk and a custom callback function
function mod5($item,$key,$arr){
if($item %5==0)$arr[]=$item;
}
array_walk( $num,'mod5',&$numbers);
echo count($numbers);
Here Output is 1 and 1. Not 11 (eleven)
You can try it
echo count($numbers)."<br>";
your solution:
Output will be 2 if you increment count variable value after enter the if condition
<?php
$num = array(4, 25, 60, 7, 8);
$count = 0;
foreach($num as $numbers) {
if (($numbers % 5) == 0) {
$count++;
}
}
echo $count;
?>
in the event you want to print the numbers also
$a=array(); //initialized empty array
$num = array(4, 25, 60, 7, 8);
foreach($num as $numbers){
if(($numbers % 5) == 0){
$a=$numbers; //store values into the array
}
}
echo count($a); // echo the count of the array
echo implode('<br>',$a);
OR if you just need the count
$a=0; //initalize $a
$num = array(4, 25, 60, 7, 8);
foreach($num as $numbers){
if(($numbers % 5) == 0){
$a++; //increment a
}
}
echo $a

Randomly interleave/zipper flat arrays without losing element order from original arrays

I want to merge / mix two arrays together, but I want it to be randomly "mixed" however NOT shuffled. For example:
$first = [1, 2, 3, 4];
$second = [10, 20, 30, 40];
Possible desired "mixes" are:
[1, 10, 20, 30, 2, 40, 3, 4]
[10, 1, 2, 20, 30, 3, 4, 40]
[1, 2, 3, 10, 20, 4, 30, 40]
Note that if we pluck the values back out we would still have the original orders of:
1, 2, 3, 4
10, 20, 30, 40
Well, there's (yet another) one possible approach:
$arr = call_user_func_array('array_merge', array_map(null, $first, $second));
print_r($arr); // [1, 10, 2, 20, 3, 30, 4, 40];
Demo. That's apparently deterministic; for random ordering each pair should be shuffled additionally. For example:
function zipShuffle($first, $second) {
return call_user_func_array('array_merge', array_map(function($a, $b) {
return mt_rand(0, 1) ? [$a, $b] : [$b, $a];
}, $first, $second));
}
... but that obviously won't be able to churn out something like [1,2,3,10,20...]. If this is required, here's another solution:
function orderedShuffle($first, $second) {
$results = [];
$stor = [$first, $second];
$i = mt_rand(0, 1);
// switching between arrays on the fly
while (list(, $v) = each($stor[$i])) {
$results[] = $v;
$i = mt_rand(0, 1);
}
// one array is gone, now we need to add all the elements
// of the other one (as its counter left where it was)
$i = 1 - $i;
while (list(, $v) = each($stor[$i])) {
$results[] = $v;
}
return $results;
}
Demo. The last function is actually quite easy to extend for as many arrays as required.
Can you try this,
<?php
$first = array(1,2,3,4);
$second = array(10,20,30,40);
$arrayMixed=array();
$firstReverse=array_reverse($first);
$secondReverse=array_reverse($second);
$firstReverseCount = count($firstReverse);
$secondReverseCount = count($secondReverse);
foreach($firstReverse as $key=>$val) {
if ($firstReverseCount>0) {
array_push($arrayMixed, array_pop($firstReverse));
if ($secondReverseCount>0) {
array_push($arrayMixed, array_pop($secondReverse));
}
}
}
$ArrayMixeddata = array_merge($arrayMixed, $second);
echo "<pre>";
print_r($ArrayMixeddata);
echo "</pre>";
?>
Not quick ways, but them works.
// with permutations
function combineShuffleOrder($first, $second)
{
// combine into one array with alternation
$firstLen = count($first);
$secondLen = count($second);
$max = max($firstLen, $secondLen);
$result = array();
for($i=0; $i < $max; $i++) {
if ($i < $firstLen)
$result[] = $first[$i];
if ($i < $secondLen)
$result[] = $second[$i];
}
// "shuffle" with permutation
$len = count($result);
for($i=1; $i<$len; $i++) {
if (rand(1, 3) % 2 == 0) {
$tmp = $result[$i-1];
$result[$i-1] = $result[$i];
$result[$i] = $tmp;
$i++; // skip one exchange
}
}
return $result;
}
// with using "shuffle" in subarray
function combineShuffleOrder2($first, $second)
{
// combine into one array with alternation
$firstLen = count($first);
$secondLen = count($second);
$max = max($firstLen, $secondLen);
$result = array();
for($i=0; $i < $max; $i++) {
$sub = array();
if ($i < $firstLen)
$sub[] = $first[$i];
if ($i < $secondLen)
$sub[] = $second[$i];
shuffle($sub);
$result = array_merge($result, $sub);
}
return $result;
}
// with using "shuffle" in subarray if sources arrays are equals by length
function combineShuffleOrder3($first, $second)
{
$max = count($first);
$result = array();
for($i=0; $i < $max; $i++) {
$sub = array(
$first[$i],
$second[$i]
);
shuffle($sub);
$result = array_merge($result, $sub);
}
return $result;
}
$first = array(1,2,3,4);
$second = array(10,20,30,40);
print_r(combineShuffleOrder($first, $second));
print_r(combineShuffleOrder2($first, $second));
print_r(combineShuffleOrder3($first, $second));
I recommend forming a single array of the two input arrays for simpler toggling. Simply loop and consume one element from a randomly selected array and push that selection into the result array. When the pool of arrays is reduced to a single array, kill the loop and append the remaining elements of the last surviving array onto the result array.
I'll use a pool of four arrays (one which is empty from the beginning) to demonstrate that the snippet is robust enough to handle a variable number of arrays, a variable number of elements in each array, and empty arrays.
Code: (Demo)
$first = [1, 2, 3, 4];
$second = [10, 20, 30, 40];
$third = [];
$fourth = ['a', 'b'];
$pool = [$first, $second, $third, $fourth];
$result = [];
while (count($pool) > 1) {
$pullFrom = array_rand($pool);
if (!$pool[$pullFrom]) {
unset($pool[$pullFrom]);
continue;
}
$result[] = array_shift($pool[$pullFrom]);
}
var_export(array_merge($result, ...$pool));
Alternatively without array_merge() and count() calls, but it makes more iterated calls of array_shift(): (Demo)
$pool = [$first, $second, $third, $fourth];
$result = [];
while ($pool) {
$pullFrom = array_rand($pool);
if (!$pool[$pullFrom]) {
unset($pool[$pullFrom]);
continue;
}
$result[] = array_shift($pool[$pullFrom]);
}
var_export($result);
Loop this script until both arrays are done.
$j = 0;
$i = 0;
$r = rand(0, 1);
if($r == 0) {
$ret .= $array1[$i];
$i++;
} elseif($r == 1) {
$ret .= $array2[$j];
$j++;
}
Of course, you have to handle a few exceptions in this code, but it might be the route.

Cumulative array

I have this array:
$a = array(1, 2, 3, 4, 5, 7, 8, 10, 12);
Is there a function to convert this to:
$b = array(1, 1, 1, 1, 2, 1, 2, 2);
So basicaly:
$b = array ($a[1]-$a[0], $a[2]-$a[1], $a[3]-$a[2], ... ,$a[n]-$a[n-1]);
Here is the code I have so far:
$a = $c = array(1, 2, 3, 4, 5, 7, 8, 10, 12);
array_shift($c);
$d = array();
foreach ($a as $key => $value){
$d[$key] = $c[$key]-$value;
}
array_pop($d);
There isn't a built-in function that can do this for you, but you could turn your code into one instead. Also, rather than making a second array, $c, you could use a regular for loop to loop through the values:
function cumulate($array = array()) {
// re-index the array for guaranteed-success with the for-loop
$array = array_values($array);
$cumulated = array();
$count = count($array);
if ($count == 1) {
// there is only a single element in the array; no need to loop through it
return $array;
} else {
// iterate through each element (starting with the second) and subtract
// the prior-element's value from the current
for ($i = 1; $i < $count; $i++) {
$cumulated[] = $array[$i] - $array[$i - 1];
}
}
return $cumulated;
}
I think php has not a build in function for this. There are many ways to solve this, but you already wrote the answer:
$len = count($a);
$b = array();
for ($i = 0; $i < $len - 1; $i++) {
$b[] = $a[$i+1] - $a[$i];
}

Getting the most repeated values in an array [duplicate]

This question already has answers here:
PHP get the item in an array that has the most duplicates
(2 answers)
Closed 1 year ago.
I have an array of numbers like this:
$array = array(1,1,1,4,3,1);
How do I get the count of most repeated value?
This should work:
$count=array_count_values($array);//Counts the values in the array, returns associatve array
arsort($count);//Sort it from highest to lowest
$keys=array_keys($count);//Split the array so we can find the most occuring key
echo "The most occuring value is $keys[0][1] with $keys[0][0] occurences."
I think array_count_values function can be useful to you. Look at this manual for details : http://php.net/manual/en/function.array-count-values.php
You can count the number of occurrences of values in an array with array_count_values:
$counts = array_count_values($array);
Then just do a reverse sort on the counts:
arsort($counts);
Then check the top value to get your mode.
$mode = key($counts);
If your array contains strings or integers only you can use array_count_values and arsort:
$array = array(1, 1, 1, 4, 3, 1);
$counts = array_count_values($array);
arsort($counts);
That would leave the most used element as the first one of $counts. You can get the count amount and value afterwards.
It is important to note that if there are several elements with the same amount of occurrences in the original array I can't say for sure which one you will get. Everything depends on the implementations of array_count_values and arsort. You will need to thoroughly test this to prevent bugs afterwards if you need any particular one, don't make any assumptions.
If you need any particular one, you'd may be better off not using arsort and write the reduction loop yourself.
$array = array(1, 1, 1, 4, 3, 1);
/* Our return values, with some useless defaults */
$max = 0;
$max_item = $array[0];
$counts = array_count_values($array);
foreach ($counts as $value => $amount) {
if ($amount > $max) {
$max = $amount;
$max_item = $value;
}
}
After the foreach loop, $max_item contains the last item that appears the most in the original array as long as array_count_values returns the elements in the order they are found (which appears to be the case based on the example of the documentation). You can get the first item to appear the most in your original array by using a non-strict comparison ($amount >= $max instead of $amount > $max).
You could even get all elements tied for the maximum amount of occurrences this way:
$array = array(1, 1, 1, 4, 3, 1);
/* Our return values */
$max = 0;
$max_items = array();
$counts = array_count_values($array);
foreach ($counts as $value => $amount) {
if ($amount > $max) {
$max = $amount;
$max_items = array($value);
} elif ($amount = $max) {
$max_items[] = $value;
}
}
$vals = array_count_values($arr);
asort($vals);
//you may need this end($vals);
echo key($vals);
I cant remember if asort sorts asc or desc by default, you can see the comment in the code.
<?php
$arrrand = '$arr = array(';
for ($i = 0; $i < 100000; $i++)
{
$arrrand .= rand(0, 1000) . ',';
}
$arrrand = substr($arrrand, 0, -1);
$arrrand .= ');';
eval($arrrand);
$start1 = microtime();
$count = array_count_values($arr);
$end1 = microtime();
echo $end1 - $start1;
echo '<br>';
$start2 = microtime();
$tmparr = array();
foreach ($arr as $key => $value);
{
if (isset($tmparr[$value]))
{
$tmparr[$value]++;
} else
{
$tmparr[$value] = 1;
}
}
$end2 = microtime();
echo $end2 - $start2;
Here check both solutions:
1 by array_count_values()
and one by hand.
<?php
$input = array(1,2,2,2,8,9);
$output = array();
$maxElement = 0;
for($i=0;$i<count($input);$i++) {
$count = 0;
for ($j = 0; $j < count($input); $j++) {
if ($input[$i] == $input[$j]) {
$count++;
}
}
if($count>$maxElement){
$maxElement = $count;
$a = $input[$i];
}
}
echo $a.' -> '.$maxElement;
The output will be 2 -> 3
$arrays = array(1, 2, 2, 2, 3, 1); // sample array
$count=array_count_values($arrays); // getting repeated value with count
asort($count); // sorting array
$key=key($count);
echo $arrays[$key]; // get most repeated value from array
String S;
Scanner in = new Scanner(System.in);
System.out.println("Enter the String: ");
S = in.nextLine();
int count =1;
int max = 1;
char maxChar=S.charAt(0);
for(int i=1; i <S.length(); i++)
{
count = S.charAt(i) == S.charAt(i - 1) ? (count + 1):1;
if(count > max)
{
max = count;
maxChar = S.charAt(i);
}
}
System.out.println("Longest run: "+max+", for the character "+maxChar);
here is the solution
class TestClass {
public $keyVal;
public $keyPlace = 0;
//put your code here
public function maxused_num($array) {
$temp = array();
$tempval = array();
$r = 0;
for ($i = 0; $i <= count($array) - 1; $i++) {
$r = 0;
for ($j = 0; $j <= count($array) - 1; $j++) {
if ($array[$i] == $array[$j]) {
$r = $r + 1;
}
}
$tempval[$i] = $r;
$temp[$i] = $array[$i];
}
//fetch max value
$max = 0;
for ($i = 0; $i <= count($tempval) - 1; $i++) {
if ($tempval[$i] > $max) {
$max = $tempval[$i];
}
}
//get value
for ($i = 0; $i <= count($tempval) - 1; $i++) {
if ($tempval[$i] == $max) {
$this->keyVal = $tempval[$i];
$this->keyPlace = $i;
break;
}
}
// 1.place holder on array $this->keyPlace;
// 2.number of reapeats $this->keyVal;
return $array[$this->keyPlace];
}
}
$catch = new TestClass();
$array = array(1, 1, 1, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 3, 1, 2, 3, 1, 1, 2, 5, 7, 1, 9, 0, 11, 22, 1, 1, 22, 22, 35, 66, 1, 1, 1);
echo $catch->maxused_num($array);

Categories