Functions

admin

1. <?php
   
2. function writeMsg() {
   
3.   echo "Hello world!";
   
4. }
   
5. 
   
6. writeMsg(); // 呼叫 the function
   
7. ?>

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結果: Hello world!

admin

arguments

1. <?php
   
2. function familyName($fname, $year) {
   
3.   echo "$fname Refsnes. Born in $year <br>";
   
4. }
   
5. 
   
6. familyName("Hege", "1975");
   
7. familyName("Stale", "1978");
   
8. familyName("Kai Jim", "1983");
   
9. ?>

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第一個呼叫的結果: Hege Refsnes. Born in 1975 其它以此類推..

admin

PHP is a Loosely Typed Language.

1. <?php
   
2. function addNumbers(int $a, int $b) {
   
3.   return $a + $b;
   
4. }
   
5. echo addNumbers(5, "5 days");
   
6. // since strict is NOT enabled "5 days" is changed to int(5), and it will return 10
   
7. ?>

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結果: 10

admin

1. <?php declare(strict_types=1); // strict requirement
   
2. 
   
3. function addNumbers(int $a, int $b) {
   
4.   return $a + $b;
   
5. }
   
6. echo addNumbers(5, "5 days");
   
7. // since strict is enabled and "5 days" is not an integer, an error will be thrown
   
8. ?>

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結果: 錯誤訊息

admin

Returning values

1. <?php declare(strict_types=1); // strict requirement
   
2. function sum(int $x, int $y) {
   
3.   $z = $x + $y;
   
4.   return $z;
   
5. }
   
6. 
   
7. echo "5 + 10 = " . sum(5, 10) . "<br>";
   
8. echo "7 + 13 = " . sum(7, 13) . "<br>";
   
9. echo "2 + 4 = " . sum(2, 4);
   
10. ?>

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let a function return a value

admin

1. <?php declare(strict_types=1); // strict requirement
   
2. function addNumbers(float $a, float $b) : int {
   
3.   return (int)($a + $b);
   
4. }
   
5. echo addNumbers(1.2, 5.2);
   
6. ?>

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結果: 6

admin

1. <?php
   
2. function add_five(&$value) {
   
3.   $value += 5;
   
4. }
   
5. 
   
6. $num = 2;
   
7. add_five($num);
   
8. echo $num;
   
9. ?>

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結果: 7