1
2
3 <?php
4 //1.连接一个heredoc定义的字符串
5 $html = <<<END
6 <div class = "divClass">
7 <ul class = "ulClass">
8 <li>
9 END
10 ."the list item"."</li></div>";
11
12 echo $html;
13
14
15
16 结果: the list item
17
18
19
20 //2.用strpos()来查找字符串,strpos必须用===或者!==,因为如果找到字符串,会返回开始处位置,值为0.
21 $email = "cccccc#cc.cc";
22 if(strpos($email,'@') === false){
23 echo 'there was no @ in the e-mail address!';
24 }
25
26 结果: there was no @ in the e-mail address!
27
28
29
30 //3.用substr()来提取一个子字符串
31 echo "<br/>";
32 $string = 'watch out for that tree';
33 $start = -17;
34 $length = 5;
35 $substring = substr($string,$start,$length);
36 echo $substring;
37
38 结果:out f
39
40
41
42 //4.用substr_replace()替换自字符串
43 //把从位置$start开始到$sold_string结尾处的所有字符
44 //替换成$new_substing
45 //$new_string = substr_replace($old_string,$new_substring,$statr);
46 echo "<br/>";
47 echo substr_replace('my pet is a blue dog.','fish','12');
48
49 //把从$start位置开始的$length个字符替换成$new_substring
50 //$new_srting = substr_replace($old_string,$new_substring,$start,$length);
51 echo "<br/>";
52 echo substr_replace('my pet is a blue dog.','green','12',4);
53
54 结果: my pet is a fish
55
56 my pet is a green dog.
57
58
59
60 //5.处理字符串中每一个字节
61
62 echo "<br/>";
63 $string = "this weekend,I'm going shoping for a pet chicken";
64 $vowels = 0;
65 for ($i = 0,$j = strlen($string);$i < $j; $i++){
66 if(strstr('aeiouAEIOU',$string[$i])){
67 $vowels++;
68 }
69 }
70 echo $vowels;
71
72 结果: 14
73
74
75
76 //6."Look and say"序列
77 echo "<br/>";
78 function lookandsay($s){
79 //将保存返回值的变量初始化为空字符串
80 $r = '';
81 //$m用于保存我们要查找的字符
82 //同时将其初始化为字符串中的第一个字符串
83 $m = $s[0];
84
85 //$n用于保存我们找到的$m的数目,将其初始化为1
86 $n = 1;
87 for($i = 1;$j = strlen($s),$i < $j;$i++){
88 //如果这个字符与上一个字符相同
89 if($s[$i] == $m){
90 //这个字符的数目加1
91 $n++;
92 }else{
93 //否则,把数目和这个字符追加到返回值
94 $r .=$n.$m;
95 //把要找的字符串设置为当前的字符
96 $m = $s[$i];
97 //并把数目重置为1
98 $n = 1;
99 }
100 }
101 //返回构建好的字符串以及最终的数目和字符
102 return $r.$n.$m;
103 }
104 for($i = 0,$s = 1;$i < 10; $i++){
105 $s = lookandsay($s);
106 echo "$s <br/>\n";
107 }
108
109 结果:
110
111 1
112 11
113 21
114 1211
115 111221
116 312211
117 13112221
118 1113213211
119 31131211131221
120 13211311123113112211
121
122 //7.按字反转字符串
123 echo "<br/>";
124 $s = "Once upon a time there was a turtle.";
125 $words = explode(' ',$s);
126 $words = array_reverse($words);
127 $s = implode(' ',$words);
128 echo $s;
129
130 结果: turtle. a was there time a upon Once
131
132
133
134 //8.简化后按字翻转字符串的代码
135 echo "<br/>";
136 $z = "this is a dog.";
137 $reversed_s = implode(' ',array_reverse(explode(' ',$z)));
138 echo $reversed_s;
139
140
141
142 结果: dog. a is this
143
144 ?>
来源：https://www.cnblogs.com/Xavier13/p/4127591.html