PHP removes the last character of a string and uses substr()_PHP tutorial

Used in today's project, remove the last character in the string
The original string is 1,2,3,4,5,6,
Remove the last character ",", the final result is 1,2, 3,4,5,6
The code is as follows:

Copy code The code is as follows:

$str = "1 ,2,3,4,5,6,";
$newstr = substr($str,0,strlen($str)-1);
echo $newstr;

Interpretation:
Use PHP’s substr() method,
Syntax: string substr(string string, int start, int [length]);
Parameter 1: Original String;
Parameter 2: starting position of cutting;
Parameter 3: intercepted length;

Use like this:
$newstr = substr($str,0,strlen ($str)-1);
Truncate from the beginning to the penultimate digit, thus removing the last ",".


The system’s own functions can also achieve this effect, two methods:
1) substr($str, 0, -1)
2) rtrim($str, ",")

substr
Get part of the string.
Syntax: string substr(string string, int start, int [length]);
Return value: string
Function type: Data processing
Content description
This function converts a string into a string Take out length characters from the string starting from the start position. If start is a negative number, it starts from the end of the string. If the omitted parameter length exists but is a negative number, it means that the length character from the bottom is obtained.
Usage example

Copy code The code is as follows:

echo substr("abcdef", 1, 3); // Return "bcd"
echo substr("abcdef", -2); // Return "ef"
echo substr("abcdef", -3, 1); // Return "d"
echo substr("abcdef", 1, -1); // return "bcde"
?>

PHP rtrim() Function

Definition and Usage
rtrim() function removes whitespace characters or other predefined characters from the end of a string. Same as chop() function.

Grammar

参数	描述
string	必需。规定要转换的字符串。
charlist	可选。规定从字符串中删除哪些字符。 如果未设置该参数，则全部删除以下字符： "