PHP sprintf function usage example tutorial-PHP Tutorial-php.cn

PHP sprintf function usage example tutorial

WBOY

Release： 2016-07-25 08:52:32

Original

1784 people have browsed it

// 1. %%: Replace %% with %
$str = 'Test the parameter %% and see what it will be replaced with';
echo sprintf($str);
//Return the result : Test what the % parameter will be replaced with (%% is replaced by a %)
// 2. %b: This parameter can only replace integer data. If it is a floating point type, only the integer part will be taken. Data after the decimal point will be ignored. If it is non-integer data. Return 0
$str = 'Parameter %b will be replaced with a binary number';
$arg = '10';
echo sprintf($str,$arg);
//Return result: Parameter 1010 will be replaced with a binary number
$arg = 10.23;
echo sprintf($str,$arg);
//Return result: parameter 1010 will be replaced with a binary number
$arg = 'abc';
echo sprintf($str,$arg);
/ /Return result: Parameter 0 will be replaced with a binary number
// 3. %c returns the ASCII code of the character encoding
$arg = 65;
$str = "The ASCII code corresponding to the number {$arg} is %c ";
echo sprintf($str,$arg);
//Return result: The number 65 corresponds to the ASCII code A
// 4. %d replaces %d in a character with int type, the data requirements are the same as $b
$str = 'ID number is %d ';
$arg = -3;
echo sprintf($str,$arg);
//Return result: ID number is -3
$arg = 4.5;
echo sprintf ($str,$arg);
//Return result: ID number is 4
$arg = 'abc';
echo sprintf($str,$arg);
//Return result: ID number is 0
/ / 5. %s - String
$str = "This is the sprintf string (%s) used for testing. I spent %f yuan today. There are %d stations from Bell Tower to Xiaozhai. Go to work";
$ arg = '%s';
echo sprintf($str,$arg,6,5);
//Return result: This is the sprintf string (%s) used for testing. I spent 6.000000 yuan today. There are 5 stops from Bell Tower to Xiaozhai. Go to work

Copy the code

Regarding parameter usage, test: When updating multiple fields of all the data in a data table, if circular updates are used, it will be very resource-intensive. Our sprintf() function will be used here. When updating the database in batches, the syntax of case then when end is generally used. The basic syntax is, for example: AUpdata Table

Set Field = CASE ID

When 1 Then 'Value1'

WHEN 2 THEN 'Value2'

Where id in (1,2,3)
Copy the code
Update the table and set the value of id = 1 to value1, the value of id = 2 to value2, and the value of id = 3 to value3. In this way, the function above the parameters combines the sql statement into such a SQL statement. Only one SQL can perform batch updates

Example:

//For example, the value corresponding to id is the following array

$info = array(1=>'Zhang San',2=>'Li Si',3=>'Wang Wu');

$ids = implode(',',array_keys($info)) //Get all ID strings

//Combined SQL

$sql = "UPDATA user SET username = CASE id";

$sql .= sprintf("WHEN %d THEN %s",$id,$username);
}
$sql .= "END WHERE id IN ($ids)";
// $model->query($sql)
Copy code
The above can complete the batch update operation, where the where clause ensures that only 3 rows of data are executed.