On the correct use way of Strpos

Firstly, the Strpos function is introduced briefly.

The Strpos function is to find the position of a character in a string, and here it is necessary to clarify its function;

This function obtains a position , if present, returns a number, otherwise returns false;

And many times we use this function to determine whether a character is present in a string;

Some students use the posture is this;

Determine if the word ' blog ' is present in the ' Bai Jun Remote blog '
if (Strpos (' Bai Jun Remote blog ', ' Blog ')}) {
If there is execution code here
echo ' presence ';
}else{
If there is no execution code here
Echo ' does not exist ';
}

This code output is ' present '; no problem; but look at the code below;

Determine if the word ' white ' is present in the ' Bai Jun Remote blog '
if (Strpos (' Bai Jun Remote blog ', ' White ')) {
If there is execution code here
echo ' presence ';
}else{
If there is no execution code here
Echo ' does not exist ';
}

The output is ' not present ' because the ' white ' is in the No. 0 position in the ' Bai Jun ' blog, and 0 indicates false in the IF;

So, if you use Strpos to determine if a character in a string must be ===false, you must use ===false , you must use ===false

Important things to say three times, the right way to use the following;

Determine if the word ' blog ' is present in the ' Bai Jun Remote blog '
if (Strpos (' Bai Jun Remote blog ', ' blog ') ===false) {
If there is no execution code here
Echo ' does not exist ';
}else{
If there is execution code here
echo ' presence ';
}

You think you've got the whole world of strpos by using = = =? No;no;no;

This guy has a hidden pit; I'll change the word.

Determine if ' 1 ' is present in ' Bai Jun Haruka blog 1 '
if (Strpos (' Bai Jun Haruka blog 1 ', 1) ===false) {
If there is no execution code here
Echo ' does not exist ';
}else{
If there is execution code here
echo ' presence ';
}

If your brain calculates the above code output is ' exist ';

Well, you're not keeping up with my routine, it's not a question of skill;

It's time to get a word for IQ.

In fact the output is ' non-existent '; careful children's shoes will find that this 1 is without the quotation marks;

The second argument of the Strpos must be of the string type;

Therefore, if you are a strpos function that is called in loops or otherwise, and is not sure of the type of the second parameter;

So the way to insure is to use strval to turn it into a string type:

Determine if ' 1 ' is present in ' Bai Jun Haruka blog 1 '
$haystack = ' Bai Jun Haruka blog 1 ';
$needle = 1;
if (Strpos ($haystack, Strval ($needle)) ===false) {
If there is no execution code here
Echo ' does not exist ';
}else{
If there is execution code here
echo ' presence ';
}

This article for Bai Jun Remote original article, reprinted without contact with me, but please specify from Bai Jun remote blog http://www.baijunyao.com

On the correct use way of Strpos