Question

我正在随机尝试从数组中选择一个文本字符串。我有一个单维数组，其结构与以下相同：

$jokes = array("Why is Peter Pan always flying? He neverlands." ,
                "My girlfriend yelled at me today saying, \"You weren't even listening just now, were you?! I thought, \"Man, what a weird way to start a conversation.\"", 
                "I used to have a job collecting leaves. I was raking it in.",
                "What's the leading cause of dry skin? Towels.",
                "I tell you what often gets overlooked - garden fences.",
                "I wear a stethoscope so that in a medical emergency I can teach people a valuable lesson about assumptions.",
                "Toasters were the first form of pop-up notifications.",
                "I love sniffing my F1 key... don't worry though, I'm trying to get help.",
                "I just ate a frozen apple. Hardcore.",
                "RIP boiled water. You will be mist.",
                "Archaeology really is a career in ruins...",
                "You know what they say about cliffhangers...",
                "I went out with a girl called Simile, I don't know what I metaphor.",
                "My server sings, it's a Dell.");

我正在使用以下方式从中选择项目：

echo json_encode($jokes[array_rand($jokes, count($jokes)-1)]);

如果我在数组中只有两个项目，那么它会完全随机化，但是一旦我超过或低于该数字，任何东西都不会返回。

Answer 1

您不能将一系列键（方形挂钩）卡入一个预期为索引的参数（圆孔）。

var_export(array_rand($jokes,count($jokes)-1));

将输出如下内容：

array (
  0 => 0,
  1 => 1,
  2 => 2,
  3 => 3,
  4 => 4,
  5 => 6,
  6 => 7,
  7 => 8,
  8 => 9,
  9 => 10,
  10 => 11,
  11 => 12,
  12 => 13,
)

你能做的是：

$rand_keys=array_rand($jokes,sizeof($jokes)-1);
var_export($rand_keys);
$rand_jokes=array_intersect_key($jokes,array_flip($rand_keys));
echo "\n",json_encode($rand_jokes);

这将输出（注意保留的键）：

array (
  0 => 0,
  1 => 1,
  2 => 2,
  3 => 3,
  4 => 4,
  5 => 5,
  6 => 6,
  7 => 8,
  8 => 9,
  9 => 10,
  10 => 11,
  11 => 12,
  12 => 13,
)
{"0":"Why is Peter Pan always flying? He neverlands.","1":"My girlfriend yelled at me today saying, \"You weren't even listening just now, were you?! I thought, \"Man, what a weird way to start a conversation.\"","2":"I used to have a job collecting leaves. I was raking it in.","3":"What's the leading cause of dry skin? Towels.","4":"I tell you what often gets overlooked - garden fences.","5":"I wear a stethoscope so that in a medical emergency I can teach people a valuable lesson about assumptions.","6":"Toasters were the first form of pop-up notifications.","8":"I just ate a frozen apple. Hardcore.","9":"RIP boiled water. You will be mist.","10":"Archaeology really is a career in ruins...","11":"You know what they say about cliffhangers...","12":"I went out with a girl called Simile, I don't know what I metaphor.","13":"My server sings, it's a Dell."}

如果您不需要保留密钥，可以使用shuffle()然后收集完整的数组，最后一个。

shuffle($jokes);
array_pop($jokes);
echo json_encode($jokes);

输出类似：

["What's the leading cause of dry skin? Towels.","Archaeology really is a career in ruins...","Why is Peter Pan always flying? He neverlands.","I tell you what often gets overlooked - garden fences.","Toasters were the first form of pop-up notifications.","I wear a stethoscope so that in a medical emergency I can teach people a valuable lesson about assumptions.","My girlfriend yelled at me today saying, \"You weren't even listening just now, were you?! I thought, \"Man, what a weird way to start a conversation.\"","My server sings, it's a Dell.","I love sniffing my F1 key... don't worry though, I'm trying to get help.","I used to have a job collecting leaves. I was raking it in.","RIP boiled water. You will be mist.","I just ate a frozen apple. Hardcore.","You know what they say about cliffhangers..."]

延迟编辑：我没有确认您的用例。

如果您只想输出一个随机笑话：

echo $jokes[array_rand($jokes)];

如果不指定array_rand()的第二个/可选参数，它将返回单个键。否则，如果您要求它返回多个键，它将返回一组键。你的第二个参数count()-1适用于一个2元素的数组，因为你只需要返回1个键（2 - 1）;处理较大的$jokes数组时，您的原始方法会出现问题。

为什么array_rand（）使用两个元素，但不是更多，或者更少？

1 个答案: