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 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,' ');

如果你不想使用replace(替换字符串中的空格而不使用replace javascript)，这里有一个替代解决方案。

var str=“狗有一条长尾巴，而且是红色的!”; var = / \ s规则{1,}/ g; STR = STR .split(规则)。加入(" "); document . write (str);

let nameCorrection = function (str) {
  let strPerfect = str.replace(/\s+/g, " ").trim();
  let strSmall = strPerfect.toLowerCase();
  let arrSmall = strSmall.split(" ");
  let arrCapital = [];
  for (let x of arrSmall.values()) {
    arrCapital.push(x[0].toUpperCase() + x.slice(1));
  }

  let result = arrCapital.join(" ");
  console.log(result);
};
nameCorrection("Pradeep kumar dHital");

//将多个空格替换为一个空格

String replacedDisplayName = displayName.replaceAll("\\s{2,}", " ");

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
}