How can i check if a string is already present withing an array before adding to it in php?
say if array is $value
$value[0]="hi";
$value[1]="hello";
$value[2]="wat";
I want to check if value exists in it before adding it to it.
5 Answers
$s='hi';
if (!in_array($s, $value)) {
$value[]=$s;
}
in_array()checks if that value (1st parameter) is in the array (2nd parameter), returns boolean (!negates it)$value[]=$swill add the value to the array with the next index
There is another tricky way if you want to add a bunch of values into an array, but only if they are not there yet. You just have to organize these new values into another array and use a combination of array_merge() and array_diff():
//your original array:
$values=array('hello', 'xy', 'fos', 'hi');
//the values you want to add if they are not in the array yet:
$values_to_add=array('hi', 'hello', 'retek');
$values=array_merge($values, array_diff($values_to_add, $values));
//$values becomes: hello, xy, fos, hi, retek
2 Comments
Glass Robot
Needs a
! before in_array
Billy Moon
should be
if(!in_array(...))You can use in_array($searchstring, $array)
in_array("hello", $value) returns true
in_array("hllo", $value) returns false
Comments
http://php.net/manual/en/function.in-array.php
if(in_array("hello", $value)) { // needle in haystack
return TRUE;
}
Comments
in_array - Checks if a value exists in an array.
In case of in_array($searchstring, $array), remember, the comparison is done in a case-sensitive manner, if the $searchstring is a "String"
Example :
- in_array("wat", $value) returns true
- in_array("what", $value) returns false.
// Observe carefully
- in_array("WAT", $value) returns false.
Comments
if you're going to create a Set, it's much better to use array keys instead of values. Simply use
$values["whatever"] = 1;
to add a value, no need to check anything.
1 Comment
No Results Found
This is not quite the same in the current context, it means you must use keys instead of values. OP said he wants to check values. This also doesn't "check" anything, so is not useful for any situation where we would need to do so, and especially in situations where the keys are not explicitly indexed, i.e.
array('apple', 'orange', 'banana').
in_array()as the first hit in google. -1 For the "no research effort" clause