Php can convert string type to int type: 1, forcing type conversion method; 2. Built-in function method; 3. Format string method. The method of forced type conversion refers to adding the target type enclosed in brackets before the variable to be converted, such as (int)$var.

Specific methods:

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1, forcing type conversion mode

Forced type conversion is a way of "putting the target type in parentheses before the variable to be converted" (from the "Type Skills" section of the PHP manual).

& lt？ Server-side programming language (abbreviation of professional hypertext preprocessor)

$ foo = " 1 "； // $foo is a string type.

$ bar =(int)$ foo； // $bar is an integer

& gt for integers, the conversion type name is int or integer.

2. Built-in function mode

The way to build a function is to use PHP's built-in function intval to convert variables.

& lt？ Server-side programming language (abbreviation of professional hypertext preprocessor)

$ foo = " 1 "； // $foo is a string type.

$ bar = intval($ foo)； // $bar is an integer

& gt3. Format string mode

The way to format the string is to format the specified variable with sprintf's %d to achieve the purpose of type conversion.

& lt？ Server-side programming language (abbreviation of professional hypertext preprocessor)

$ foo = " 1 "； // $foo is a string type.

$bar = sprintf("%d "，$ foo)； // $bar is a string type

& gt Strictly speaking, the conversion result of sprintf is still a string type, so it should not be regarded as a way to convert a string into an integer. But the string value he processed has indeed become "an integer that is forcibly converted into a string type".