Home > Article > Backend Development > Similarities and differences between PHP functions and Flutter functions
The main differences between PHP and Flutter functions are declaration, syntax and return type. PHP functions use implicit return type conversion, while Flutter functions explicitly specify return types; PHP functions can specify optional parameters through ?, while Flutter functions use required and [] to specify required and optional parameters; PHP functions use = to pass naming Parameters, while Flutter functions use {} to specify named parameters.
PHP functions
function sum($a, $b) { return $a + $b; }
Flutter function
int sum(int a, int b) => a + b;
PHP function
function
Yes Specify optional parameters via ?
and set default values via =
. Named parameters are passed using =
.
function sum($a, $b = 0) { return $a + $b; } sum(1); // 1 sum(1, 2); // 3
Flutter function
Flutter function uses required
to specify required parameters, []
to specify optional parameters,{}
Specify named parameters.
int sum(int a, {int b = 0}) => a + b; sum(1); // 1 sum(1, 2); // 3
PHP function
PHP function uses implicit return type conversion and returns null
by default.
function add(int $a, int $b) { return $a + $b; // 返回 int 型 }
Flutter function
Flutter function explicitly specifies the return type.
int sum(int a, int b) => a + b;
PHP
<?php function get_username($id) { $db = connect_database(); $result = $db->query("SELECT username FROM users WHERE id='$id'"); if ($result->num_rows > 0) { return $result->fetch_assoc()['username']; } else { return null; } } $username = get_username(1); echo $username; // "john" ?>
Flutter
String? getUsername(int id) { // 连接数据库并查询数据... // 实际实现省略 // 假设返回的用户名为 "john" return "john"; } void main() { String? username = getUsername(1); print(username); // "john" }
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