Use the str_pad function in PHP to generate product numbers in the form of numerical increments_PHP tutorial

Solution: $str="QB".str_pad(($maxid[0]["max(id)"]+1),5,"0",STR_PAD_LEFT );

where $maxid[0 ]["max(id)"]+1) is to use the max function to find the value with the largest ID from the database. The ID is the primary key and will not be repeated.

str_pad() function pads a string to the specified length.

Grammar

str_pad(string,length,pad_string,pad_type)

Parameters

Description

string

Required. Specifies the string to be filled.

length

Required. Specifies the length of the new string. If the value is less than the length of the original string, no operation is performed.

pad_string

Optional. Specifies the string used for padding. The default is blank.

pad_type

Optional. Specifies the side of the padding string. Possible values:

参数	描述
string	必需。规定要填充的字符串。
length	必需。规定新字符串的长度。如果该值小于原始字符串的长度，则不进行任何操作。
pad_string	可选。规定供填充使用的字符串。默认是空白。
pad_type	可选。规定填充字符串的那边。可能的值： STR_PAD_BOTH – 填充到字符串的两头。如果不是偶数，则右侧获得额外的填充。 STR_PAD_LEFT – 填充到字符串的左侧。 STR_PAD_RIGHT – 填充到字符串的右侧。这是默认的。

• STR_PAD_BOTH – Pad to both ends of the string. If it's not an even number, the right side gets extra padding.
• STR_PAD_LEFT – Pad to the left side of the string.
• STR_PAD_RIGHT – Pad to the right side of the string. This is the default.

http://www.bkjia.com/PHPjc/313501.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/313501.htmlTechArticleSolution: $str="QB".str_pad(($maxid[0]["max(id) "]+1),5,"0",STR_PAD_LEFT ); where $maxid[0]["max(id)"]+1) is to use the max function to find the value with the largest ID from the database,...