如何在 PHP 中的空格后删除所有内容？
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How do I remove everything after a space in PHP?
提问by AlphaApp
I have a database that has names and I want to use PHP replace after the space on names, data example:
我有一个有名字的数据库，我想在名字上的空格后使用 PHP 替换，数据示例：
$x="Laura Smith";
$y="John. Smith"
$z="John Doe";
I want it to return
我想要它回来
Laura
John.
John
回答by Codemonkey
Just to add it into the mix, I recently learnt this technique:
只是为了将其添加到组合中，我最近学习了这种技术：
list($s) = explode(' ',$s);
I just did a quick benchmark though, because I've not come across the strtok method before, and strtok is 25% quicker than my list/explode solution, on the example strings given.
不过，我只是做了一个快速基准测试，因为我之前没有遇到过 strtok 方法，并且在给出的示例字符串中，strtok 比我的列表/爆炸解决方案快 25%。
Also, the longer/more delimited the initial string, the bigger the performance gap becomes. Give a block of 5000 words, and explode will make an array of 5000 elements. strtok will just take the first "element" and leave the rest in memory as a string.
此外，初始字符串越长/分隔越多，性能差距就越大。给出一个 5000 个单词的块，explode 将生成一个包含 5000 个元素的数组。strtok 将只取第一个“元素”，并将其余部分作为字符串留在内存中。
So strtok wins for me.
所以 strtok 为我赢了。
$s = strtok($s,' ');
回答by TheBlackBenzKid
Do this, this replaces anything after the space character. Can be used for dashes too:
这样做，这会替换空格字符之后的任何内容。也可以用于破折号：
$str=substr($str, 0, strrpos($str, ' '));
回答by Naveen Kumar
回答by oopbase
There is no need to use regex, simply use the explode method.
不需要使用正则表达式，只需使用explode方法即可。
$item = explode(" ", $x);
echo $item[0]; //Laura
回答by symcbean
The method provided by TheBlackBenzKid is valid for the question - however when presented with an argument which contains no spaces, it will return a blank string.
TheBlackBenzKid 提供的方法对该问题有效 - 但是，当提供不包含空格的参数时，它将返回一个空白字符串。
Although regexes will be more computationally expensive, they provide a lot more flexibiltiy, e.g.:
尽管正则表达式的计算成本更高，但它们提供了更多的灵活性，例如：
function get_first_word($str)
{
return (preg_match('/(\S)*/', $str, $matches) ? $matches[0] : $str);
}
回答by Black Mamba
This answer will remove everything after the first space and not the last as in case of accepted answer.Using strposand substr
这个答案将删除第一个空格之后的所有内容，而不是最后一个空格，就像接受的答案一样。使用strpos和substr
$str = "CP hello jldjslf0";
$str = substr($str, 0, strpos( $str, ' '));
echo $str;
回答by mickmackusa
There is an unmentioned function call that I consistently use for this exact task.
有一个未提及的函数调用，我一直用于这个确切的任务。
strstr()with a third parameter of true, will return the substring beforethe first occurrence of the needle string.
strstr()的第三个参数为 true，将返回第一次出现针串之前的子串。
Code: (Demo)
代码：（演示）
$array = [
'x' => 'Laura Smith',
'y' => 'John. Smith',
'z' => 'John Doe'
];
foreach ($array as $key => $value) {
$array[$key] = strstr($value, ' ', true);
}
var_export($array);
Output:
输出：
array (
'x' => 'Laura',
'y' => 'John.',
'z' => 'John',
)
Note, if the needle is not found in the string, strstr()will return false.
注意，如果在字符串中找不到针，strstr()将返回false。
p.s.
ps
- Because there are single-function techniques to perform this task, there is no compelling reason to use multiple-function techniquesto do the same work.
- Because the needle is a static string (a space) there is absolutely no reason to introduce the overhead of a regex call.
- If anyone is considering the use of
explode()to produce a temporary array instead of a more direct "string in - string out" operation such asstrtok()orstrstr(), be sure to declare the third parameter ofexplode()using the integer that represents your targeted element's index + 1 -- this way the function will stop making new elements as soon as it has isolated the substring that you seek.
- 因为有单功能技术可以执行此任务，所以没有令人信服的理由使用多功能技术来完成相同的工作。
- 因为指针是一个静态字符串（一个空格），所以绝对没有理由引入正则表达式调用的开销。
- 如果有人正在考虑使用
explode()来生成临时数组而不是更直接的“字符串输入-字符串输出”操作，例如strtok()orstrstr()，请务必声明explode()使用表示目标元素索引 + 1 的整数的第三个参数——这样，一旦分离出您要查找的子字符串，该函数将停止创建新元素。
回答by mickmackusa
You can do also like this
你也可以这样做
$str = preg_split ('/\s/',$x);
print $str[0];
回答by Dirk McQuickly
$x="Laura Smith";
$temparray = implode(' ', $x);
echo $temparray[0];
$x="劳拉史密斯"; $temparray = implode(' ', $x); 回声 $temparray[0];
I'm sorry, sometimes mix up implode and explode...
对不起，有时会混淆内爆和爆炸...
