消毒整数

删除除数字，加号和减号以外的所有字符。

var_dump(filter_var(1, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var(-1, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var(+1, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var(1.00, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var(+1.00, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var(-1.00, FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('1', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('-1', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('+1', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('1.00', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('+1.00', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('-1.00', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('1 unicorn', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('-1 unicorn', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var('+1 unicorn', FILTER_SANITIZE_NUMBER_INT));
var_dump(filter_var("!#$%&'*+-=?^_`{|}~@.[]0123456789abcdefghijklmnopqrstuvwxyz", FILTER_SANITIZE_NUMBER_INT));

结果：

string(1) "1"
string(2) "-1"
string(1) "1"
string(1) "1"
string(1) "1"
string(2) "-1"
string(1) "1"
string(2) "-1"
string(2) "+1"
string(3) "100"
string(4) "+100"
string(4) "-100"
string(1) "1"
string(2) "-1"
string(2) "+1"
string(12) "+-0123456789"