去除字符串中空格的正则表达式

str.replace(/\s/g, '')

/正则表达式/   这两个斜杠是JS正则表达式的规则

\s   表示字符串中的空字符

g   表示全部匹配

The \s (lowercase s) matches a whitespace (blank, tab \t, form-feed \f and newline \r or \n).

On the other hand, the \S+ (uppercase S) matches anything that is not matched by \s, i.e., non-whitespace.

In regex, the uppercase metacharacter denotes the inverse of the lowercase counterpart, for example, \w for word character and \W for non-word character.

1. The \s (lowercase s) matches a whitespace (blank, tab \t, form-feed \f and newline \r or \n). On the other hand, the \S+ (uppercase S) matches anything that is not matched by \s, i.e., non-whitespace. In regex, the uppercase metacharacter denotes the inverse of the lowercase counterpart, for example, \w for word character and \W for non-word character.