Strings for newbies to PHP

1. String variable

String variable is used to store and process text

<?php
	$a = "hello world" ;
	echo $a;
?>

Create a string named a variable and assign the value to "Hello world!". Then we output the value of a variable

The concatenation operator in the string

There is only one concatenation operator in the string " . " Is this right? Two strings are linked together

<?php
	$a = "hello world"."! welcome" ;
	echo $a;
?>

strlen() function

Sometimes it is useful to know the length of the string value

<?php
	$a = "hi hello world";
	echo strpos($a,'l');
?>

Note: The number of characters is only 12, but there are 2 spaces. Spaces are also characters. The output result is 14

strpos() function

strpos() function is used to find a character or a specified piece of text in a string

<?php
	$a = "hi hello world";
	echo strpos($a,'l');
?>

Note: The subscript of the string starts with 0, that is, the position of h in the above code is 0, Then the position of l is in the fifth position, so the output is 5 instead of 6

There are many functions that operate on strings in php, as shown in the figure below

For specific usage, please refer to the manual or Baidu