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+/, '') )

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, " ");

更健壮的:

function trim(word)
{
    word = word.replace(/[^\x21-\x7E]+/g, ' '); // change non-printing chars to spaces
    return word.replace(/^\s+|\s+$/g, '');      // remove leading/trailing spaces
}

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 myregexp = new RegExp(/ {2,}/g);

str = str.replace(myregexp,' ');

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

编辑: 如果你想替换所有类型的空白字符，最有效的方法是这样的:

str = str.replace(/\s{2,}/g,' ');