I m so confusing here with this problem, please help me to solve this.
I have 2 array data,
$one = array ("sinta","jojo","wawan","silvie");
$two = array ("eat","sleep","breakfast","sport");
I want to create a random output array from this 2 array, and i want this only pick 2 random array from each array data, so maybe the result would be like this :
$three = array ("sinta","silvie","breakfast","eat");
or
$three = array("jojo","silvie","eat","sleep");
and etc..
Normally I don't like code only answers, but:
$three = array_merge(array_rand($one, 2), array_rand($two, 2));
shuffle($three);
You can read up on array_rand and array_merge and shuffle in the linked manuals. This code picks 2 elements each from $one and $two at random, and then randomizes the order of the result.
Small warning: If you have string keys in your arrays they will be destroyed.
$three[0] = $one[rand(0,3)];
$three[1] = $one[rand(0,3)];
$three[2] = $two[rand(0,3)];
$three[3] = $two[rand(0,3)];
thats the logic - I did not php for a while so check the syntax, please.
Now you have to assure that rand is not picking the same value twice or youhave to eat two breakfasts :-)
Related
I'm searching for an algorithm to remove gaps between numbers. Example of my problem:
Here is a range of integers: [1,2,3,4,9,10,11,17...]
I need to make those numbers like this: [1,2,3,4,5,6,7,8...]
Can anyone provide me with a working example of PHP code to obtain such a result?
You should fetch min and max from an array and create the range,
$min = min($arr);
$max = max($arr);
print_r(range($min,$max));
You can make by using range function as:
// given array 2,4,6 and 9 are missing.
$arr1 = array(1,3,5,7,8,10);
// construct a new array using range function by giving min(given array) and max(given array) value
$arr2 = range(min($arr1),max($arr1));
This question already has answers here:
Merge two flat indexed arrays of equal size so that values are pushed into the result in an alternating fashion
(2 answers)
Closed last month.
I have two arrays:
$array1 = array("A","One","C","Z");
$array2 = array("B","K","2","5");
Is there some built-in PHP way to get a final array with (I don't know how to say it, maybe 1-1 correspondence addition) alternate keys appended to each other like this
$final_array = array("A","B","One","K","C","2","Z","5");
If I use array_merge, I get:
$final_array = array("A","One","C","Z","B","K","2","5")
But that's exactly what an array_merge does. Is there any workaround other than looping?
Try this:
$array1 = array(1,3,5,7);
$array2 = array(2,4,6,8);
$final_array = array_merge($array1,$array2);
sort($final_array);
print_r($final_array);
Hope this helps. Sorted the array using the sort function.
So far I have done the following:
$row = mysql_fetch_assoc($result);
$row2 = mysql_fetch_assoc($result);
$duplicates = array_intersect($row, $row2);
How do I combine the 2 arrays and make a new one that just contains one instance of the previously repeated variables? (so if array $row contained the variable 'apple' 2 times and the array $row2 contained the variable 'apple' 3 times, in the new, merged array, 'apple' would only appear once.
edit: I didn't realize that the array_merge() function works differently for numbers than compared to strings. I gave the 'apple' example above but my arrays are dealing with product IDs which are numbers. PHP manual says
If, however, the arrays contain numeric keys, the later value will not
overwrite the original value, but will be appended.
and I need help in merging arrays with numbers, what should I do?
You can use
$c = array_merge($a, $b);
http://php.net/manual/en/function.array-merge.php
if you want to remove duplicate values after the merge then use array_unique();
so...
$c = array_unique(array_merge($a, $b));
I have the following array:
$array = array(1,0,0,0,1,1,1,1,0,1,1,1,1,0,1,1,0,1,0,0,1,0,1);
I want split it up into individual arrays so that each array contains seven or less values.
So for example the first array will become:
$one = array(1,0,0,0,1,1,1)
$two = array(1,0,1,1,1,1,0)
$three = array(1,1,0,1,0,0,1);
$four = array(0,1);
Also how would you count the number of times 1 occurs in array one?
array_chunk() is what you are looking for.
$splitted = array_chunk($array, 7);
For counting the occurences I would be lazy. If your arrays only contain 1s or 0s, then a simple array_sum() would do:
print array_sum($splitted[0]); // for the first chunk
I want split it up into individual arrays so that each array contains seven or less values.
Use array_chunk(), which is made expressly for this purpose.
Also how would you count the number of times 1 occurs in array one?
Use array_count_values().
$one = array(1,0,0,0,1,1,1);
$one_counts = array_count_values($one);
print_r($one_counts);
// prints
Array
(
[0] => 3
[1] => 4
)
Assuming you want to preserve the contents of the array, I'd use array_slice() to extract the needed number of elements from the array, incrementing the '$offset' by the required count each time until the array was exhausted.
And as to your second question, try:
$num_ones=count(preg_grep(/^1$/,$array));
PHP.
$a['0']=1;
$a[0]=2;
Which is proper form?
In the first example you use a string to index the array which will be a hashtable "under the hood" which is slower. To access the value a "number" is computed from the string to locate the value you stored. This calculation takes time.
The second example is an array based on numbers which is faster. Arrays that use numbers will index the array according to that number. 0 is index 0; 1 is index 1. That is a very efficient way of accessing an array. No complex calculations are needed. The index is just an offset from the start of the array to access the value.
If you only use numbers, then you should use numbers, not strings. It's not a question of form, it's a question of how PHP will optimize your code. Numbers are faster.
However the speed differences are negligible when dealing with small sizes (arrays storing less than <10,000 elements; Thanks Paolo ;)
In the first you would have an array item:
Key: 0
Index: 0
In the second example, you have only an index set.
Index: 0
$arr = array();
$arr['Hello'] = 'World';
$arr['YoYo'] = 'Whazzap';
$arr[2] = 'No key'; // Index 2
The "funny" thing is, you will get exactly the same result.
PHP (for whatever reason) tests whether a string used as array index contains only digits. If it does the string is converted to int or double.
<?php
$x=array(); $x['0'] = 'foo';
var_dump($x);
$x=array(); $x[0] = 'foo';
var_dump($x);
For both arrays you get [0] => foo, not ["0"] => foo.
Or another test:<?php
$x = array();
$x[0] = 'a';
$x['1'] = 'b';
$x['01'] = 'c';
$x['foo'] = 'd';
foreach( $x as $k=>$v ) {
echo $k, ' ', gettype($k), "\n";
}0 integer
1 integer
01 string
foo string
If you still don't believe it take a look at #define HANDLE_NUMERIC(key, length, func) in zend_hash.h and when and where it is used.
You think that's weird? Pick a number and get in line...
If you plan to increment your keys use the second option. The first one is an associative array which contains the string "0" as the key.
They are both "proper" but have the different side effects as noted by others.
One other thing I'd point out, if you are just pushing items on to an array, you might prefer this syntax:
$a = array();
$a[] = 1;
$a[] = 2;
// now $a[0] is 1 and $a[1] is 2.
they are both good, they will both work.
the difference is that on the first, you set the value 1 to a key called '0'
on the second example, you set the value 2 on the first element in the array.
do not mix them up accidentally ;)