Spliting and storing string in an array php

Question

I have a string

$descr = "Hello this is a test string";

What I am trying to do is to split the string and store each word which is separated using space into separate array index in PHP. Should I use

$myarray = preg_split("[\s]",$descr);

Expected outcome :

$myarray(1) : hello
$myarray(2) : this
$myarray(3) : is
$myarray(4) : a
$myarray(5) : test
$myarray(6) : string

Each number denotes array index

Answer 1

$descr = "Hello this is a test string";
$myarray = explode(' ', $descr);

Will produce:

Array
(
    [0] => Hello
    [1] => this
    [2] => is
    [3] => a
    [4] => test
    [5] => string
)

Use the explode function which takes the delimiter as the first parameter and the string variable you want to "explode" as the second parameter. Each word separated by the sent delimiter will be an element in the array.

Answer 2

You need to use explode() like below:-

$myarray = explode(' ', $descr);
print_r($myarray);

Output:-https://eval.in/847916

To re-index and lowercase each word in your array do like this:-

<?php

$descr = "Hello this is a test string";

$myarray = explode(' ', $descr);

$myarray = array_map('strtolower',array_combine(range(1, count($myarray)), array_values($myarray)));
print_r($myarray);

Output:-https://eval.in/847960

To get how many elements are there in the array:-

echo count($myarray);

Answer 3

One of the best way is to use str_word_count

print_r(str_word_count($descr , 1));

Answer 4

This question is seeking support for a task comprised from 3 separate procedures.

1. How to split a string on spaces to generate an array of words? (The OP has a suboptimal, yet working solution for this part.)

   • Because the pattern is only seeking out "spaces" between words, the pattern could be changed to / /. This eliminates the check for additional white-space characters beyond just the space.
   • Better/Faster than a regex-based solutions would be to split the string using string functions.
     
     • explode(' ',$descr) would be the most popular and intuitive function call.
     • str_word_count($descr,1) as Ravi Hirani pointed out will also work, but is less intuitive.
       A major benefit to this function is that it seamlessly omits punctuation -- for instance, if the the OP's sample string had a period at the end, this function would omit it from the array!
       
       Furthermore, it is important to note what is considered a "word":

       For the purpose of this function, 'word' is defined as a locale dependent string containing alphabetic characters, which also may contain, but not start with "'" and "-" characters.

2. How to generate an indexed array with keys starting from 1?

   • Bind a generated "keys" array (from 1) to a "values" array:
     • $words=explode(' ',$descr); array_combine(range(1,count($words)),$words)
   • Add a temporary value to the front of the indexed array ([0]), then remove the element with a function that preserves the array keys.
     • array_unshift($descr,''); unset($descr[0]);
     • array_unshift($descr,''); $descr=array_slice($descr,1,NULL,true);
3. How to convert a string to all lowercase? (it was hard to find a duplicate -- this a RTM question)
   • lcfirst($descr) will work in the OP's test case because only the first letter of the first word is capitalized.
   • strtolower($descr) is a more reliable choice as it changes whole strings to lowercase.
   • mb_strtolower($descr) if character encoding is relevant.
   • Note: ucwords() exists, but lcwords() does not.

---

There are so many paths to a correct result for this question. How do you determine which is the "best" one? Top priority should be Accuracy. Next should be Efficiency/Directness. Followed by some consideration for Readability. Code Brevity is a matter of personal choice and can clash with Readability.

With these considerations in mind, I would recommend these two methods:

Method #1: (one-liner, 3-functions, no new variables)

$descr="Hello this is a test string";
var_export(array_slice(explode(' ',' '.strtolower($descr)),1,null,true));

Method #2: (two-liner, 3-functions, one new variable)

$descr="Hello this is a test string";
$array=explode(' ',' '.strtolower($descr));
unset($array[0]);
var_export($array);

Method #2 should perform faster than #1 because unset() is a "lighter" function than array_slice().

Explanation for #1 : Convert the full input string to lowercase and prepend $descr with a blank space. The blank space will cause explode() to generate an extra empty element at the start of the output array. array_slice() will output generated array starting from the first element (omitting the unwanted first element).

Explanation for #2 : The same as #1 except it purges the first element from generated array using unset(). While this is faster, it must be written on its own line.

Output from either of my methods:

array (
  1 => 'hello',
  2 => 'this',
  3 => 'is',
  4 => 'a',
  5 => 'test',
  6 => 'string',
)

Related / Near-duplicate:

• php explode and force array keys to start from 1 and not 0