php 练习题

book.php

<?php

/* 亚马逊举办图书优惠活动，满100减10，满200减50，满300减80，满400减120，满500减200。
 * tree买了1本书价格是 54.9， noodles买了3本书45.8  36.5  50.2，
 * laker买了5本书21.3 45.6 39.5 62.5 20.5 
 * fen买了8本书 50.6 20.4  36.7  45.6  19.8  60.5 44.3 55.0
 * 70买了10本书  47.8  30.6  15.6  56.8  30.0  29.8 60.8  70.9 69.9  116.7,，
 * 请计算出各位需要付的金额。*/

$tree = ["tree", [54.9]];
$noodles = ["noodles", [45.8, 36.5, 50.2]];
$laker = ["laker", [21.3, 45.6, 39.5, 62.5, 20.5]];
$fen = ["fen", [50.6, 20.4, 36.7, 45.6, 19.8, 60.5, 44.3, 55.0]];
$seventy = ["seventy", [47.8, 30.6, 15.6, 56.8, 30.0, 29.8, 60.8, 70.9, 69.9, 116.7]];

function price($shopping_list) {
  $total = array_sum($shopping_list);
  if ($total > 500) {
    $aftermath = $total - 200;
  }
  elseif ($total > 400) {
    $aftermath = $total - 120;
  }
  elseif ($total > 300) {
    $aftermath = $total -80;
  }
  elseif ($total > 200) {
    $aftermath = $total -50;
  }
  elseif ($total > 100) {
    $aftermath = $total -10;
  }
  else {
    $aftermath = $total;
  }
  return $aftermath;
}


array_map(
  function($sl) {
    echo $sl[0], ' need to pay ', price($sl[1]), "\n";
  },
  [$tree, $noodles, $laker, $fen, $seventy]
);

get_image_name.php

<?php

# 获取<img alt="SegmentFault" src="http://s.segmentfault.com/img/logo.png?13.10.21.1">里图片名称

$URL = '<img alt="SegmentFault" src="http://s.segmentfault.com/img/logo.png?13.10.21.1">';

function get_image_name($url) {
  preg_match('/(img\/)([a-z0-9]+\.[a-z]+)/', $url, $image_name);
  return $image_name[2];
}

echo get_image_name($URL);

io.php

<?php

# 将we're the sfer!写入sf.txt

$to_write_file = "sf.txt";
$to_write_content = "we're the sfer!";
file_put_contents($to_write_file, $to_write_content);

# 将www.baidu.com内容追加sf.txt
file_put_contents($to_write_file, 'www.baidu.com', FILE_APPEND | LOCK_EX);

php_0.md

1. 搭好php环境，写出第一个hello word。

<?php
echo "hello world";
?>

2. 输出你邮箱的用户名和域名

<?php

list($user, $domain) = explode('@', 'weakish@gamil.com');
echo $user;
echo $domain;

?>

3. 匹配出blog.segmentfault.com的主域名segmentfault.com

<?php

list($main_domain, $top_level_domain) = array_slice(explode('.', 'dev.blog.segmentfault.com'), -2);
echo $main_domain, '.', $top_level_domain;

?>

remove_numbers.php

<?php

const FILE_NAME = 'city.txt';

$city_list = explode("\n", file_get_contents(FILE_NAME));

$result = implode("\n", preg_grep("/[0-9]/", $city_list, PREG_GREP_INVERT));

file_put_contents(FILE_NAME, $result);

不错，会用list，explode也找得很准确。
域名匹配其实有一个php函数parse_url

学习了

["tree", [54.9]] 这个语法只能在 php>5.4 工作