javascript - 在名字/姓氏验证中只允许一个空格的正则表达式

Question

我正在尝试编写一个正则表达式来删除单词开头的空格，而不是单词后面的空格，并且只删除单词后面的一个空格。

使用正则表达式:

var re = new RegExp(/^([a-zA-Z0-9]+\s?)*$/);

测试示例:

1) test[space]ing - Should be allowed 
2) testing - Should be allowed 
3) [space]testing - Should be allowed but have to trim the space at the first
4) testing[space] - Should be allowed but have to trim the space at the last 
5) testing[space][space] - should be allowed but have to trim the space at the last  
6) test[space][space]ing - one space should be allowed but the remaining spaces have to be trimmed.

知道如何使用正则表达式实现这一点吗？

编辑:

我有这个，

 var regExp = /^(\w+\s?)*\s*$/;
if(regExp.test($('#FirstName').val())){
                    $('#FirstName').val().replace(/\s+$/, '');
                }else{
                    var elm = $('#FirstName'),
                    msg = 'First Name must consist of letters with no spaces';
                    return false;
                }

Answer 1

使用捕获组:

var re = /^\s+|\s+$|(\s)\s+/g;
'test ing'.replace(re, '$1')   // => 'test ing'
'testing'.replace(re, '$1')    // => 'testing'
' testing'.replace(re, '$1')   // => 'testing'
'testing '.replace(re, '$1')   // => 'testing'
'testing  '.replace(re, '$1')  // => 'testing'
'test  ing'.replace(re, '$1')  // => 'test ing'