What are the methods for integer conversion in php?

#What are the integer conversion methods in php?

In PHP, we can use 3 ways to convert strings into integers.

1. Forced type conversion method

Forced type conversion method is the method of "adding the target type enclosed in parentheses before the variable to be converted".

<?php 
$foo = "1"; // $foo 是字符串类型 
$bar = (int)$foo; // $bar 是整型 
?>

For integers, the cast type name is int or integer.

2. Built-in function method

The built-in function method uses PHP’s built-in function intval to convert variables.

<?php 
$foo = "1"; // $foo 是字符串类型 
$bar = intval($foo); // $bar 是整型 
?>

The format of the intval function is:

int intval(mixed $var [, int $base]);

3. Format string method

The format string method uses sprintf's % d formats the specified variable to achieve type conversion.

<?php 
$foo = "1"; // $foo 是字符串类型 
$bar = sprintf("%d", $foo); // $bar 是字符串类型 
?>

Strictly speaking, the conversion result of sprintf is still string type, so it should not be regarded as a way to convert strings into integers. But the string value after his processing has indeed become "an integer that is forced to be converted to a string type."

Performance:

int > intval > sprintf

From a readability perspective, the sprintf method code is relatively long, and the result may need to be cast again, and intval Functions are typical procedure-oriented conversions, while forced type conversions more directly convey the idea of ​​"I want to convert" to readers.

In terms of efficiency, forced type conversion is also the fastest conversion method (the integer variable value can be obtained directly).

Recommended tutorial: "PHP Tutorial"

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