假设你还想覆盖制表符、换行符等，只需将\s\s+替换为' ':

string = string.replace(/\s\s+/g, ' ');

如果你真的只想覆盖空格(而不是制表符，换行符等)，可以这样做:

string = string.replace(/  +/g, ' ');

这是一种解决方案，尽管它将针对所有空格字符:

"The      dog        has a long tail,      and it is RED!".replace(/\s\s+/g, ' ')

"The dog has a long tail, and it is RED!"

编辑:这可能更好，因为它的目标是一个空格后面跟着一个或多个空格:

"The      dog        has a long tail,      and it is RED!".replace(/  +/g, ' ')

"The dog has a long tail, and it is RED!"

替代方法:

"The      dog        has a long tail,      and it is RED!".replace(/ {2,}/g, ' ')
"The dog has a long tail, and it is RED!"

我没有单独使用/\s+/，因为它可以多次替换跨越1个字符的空格，而且可能效率较低，因为它的目标超过了必要的范围。

我没有深入测试任何这些，所以如果有bug，我就不知道了。

另外，如果你要做字符串替换，记得重新分配变量/属性到它自己的替换，例如:

var string = 'foo'
string = string.replace('foo', '')

使用jQuery.prototype.text:

var el = $('span:eq(0)');
el.text( el.text().replace(/\d+/, '') )

一种更健壮的方法:如果存在初始空格和尾随空格，则该方法也会删除它们。例如:

// NOTE the possible initial and trailing spaces
var str = "  The dog      has a long   tail, and it     is RED!  "

str = str.replace(/^\s+|\s+$|\s+(?=\s)/g, "");

// str -> "The dog has a long tail, and it is RED !"

你的例子没有这些空格，但它们也是一个非常常见的场景，而公认的答案只是把它们精简成单个空格，比如:“the…红色!，这不是您通常需要的。

var string = "The dog      has a long   tail, and it     is RED!";
var replaced = string.replace(/ +/g, " ");

或者如果你也想替换制表符:

var replaced = string.replace(/\s+/g, " ");

var text = `xxx  df dfvdfv  df    
                     dfv`.split(/[\s,\t,\r,\n]+/).filter(x=>x).join(' ');

结果:

"xxx df dfvdfv df dfv"

尝试用一个空格替换多个空格。

<script type="text/javascript">
    var myStr = "The dog      has a long   tail, and it     is RED!";
    alert(myStr);  // Output 'The dog      has a long   tail, and it     is RED!'

    var newStr = myStr.replace(/  +/g, ' ');
    alert(newStr);  // Output 'The dog has a long tail, and it is RED!'
</script>

阅读更多@用单个空格替换多个空格