check white space of a string at the begin [duplicate] - php

Question

This question already has answers here:
Check for whitespace at beginning of string
(4 answers)
Closed 8 years ago.
Is there any way to check the white space at the begin of a string ? I have tried strpos but look like it doesn't work. I use $_POST['text']=" hi" and it output ok in my code. It suppose to be an error.
<form action="#" method="POST">
text <input type='text' name='text'/><br/>
<input type='submit' value='submit'/>
</form>
<?php
if(isset($_POST['text']) && !empty($_POST['text']))
{
if(strpos($_POST['text'],' '))
{
echo 'found white space';
}
else
{
echo 'not found';
}
}
else
{
echo 'none';
}

Answer 1

strpos() will search through the whole string. At the end and in the middle.
Also, you should always use !== false resp. === false when using with strpos().
You can use this for your problem:
if (ctype_space($_POST['text'][0])) {
}
ctype_space() is better than $_POST['text'][0] == ' ', since it also checks for tabs or null characters etc.
PS: If you simply want to remove whitespaces, use trim() . If you just want to remove at the left, you can use ltrim() .

Answer 2

With strpos you find all spaces in your string (or better, first space in your string, not directly first character). Use substr for testing first character.
if (!empty($_POST['text'])) {
if (substr($_POST['text'], 0, 1) == ' ') {
echo 'First char is space';
} else {
echo 'First char isn\'t space';
}
} else {
echo 'String is empty.';
}

Answer 3

if(ltrim($str) == $str)
{
echo 'No Space';
}
else
{
echo 'There are space';
}
This code will check if there are space at the begin of a string.

Answer 4

I got the answer for you. The answer is quite simple you have to just use false and true statement to check weather it has space or not. I have edited your answer please check it.
<form action="#" method="POST">
text <input type='text' name='text'/><br/>
<input type='submit' value='submit'/>
</form>
<?php
if(isset($_POST['text']) && !empty($_POST['text']))
{
$sx=strpos($_POST['text'],' ');
if($sx==true)
{
echo 'found white space';
}
else
{
echo 'not found';
}
}
else
{
echo 'none';
}
Tell if it works