Question

我正在使用以下正则表达式：

/^(?:1|0?\.\d)$/

我需要在0.1和1之间的范围内，每个数字在点之前和之后。例如：

0.1 valid
1 valid
0.111 not valid
011.2 not valid

有效数字为[0.1-0.9]和1

Answer 1

使用

/^(?:1|0?\.[1-9])$/

请参见proof

说明

--------------------------------------------------------------------------------
  ^                        the beginning of the string
--------------------------------------------------------------------------------
  (?:                      group, but do not capture:
--------------------------------------------------------------------------------
    1                        '1'
--------------------------------------------------------------------------------

   |                        OR
--------------------------------------------------------------------------------
    0?                       '0' (optional (matching the most amount
                             possible))
--------------------------------------------------------------------------------
    \.                       '.'
--------------------------------------------------------------------------------
    [1-9]                    any character of: '1' to '9'
--------------------------------------------------------------------------------
  )                        end of grouping
--------------------------------------------------------------------------------
  $                        before an optional \n, and the end of the
                           string

Answer 2

以下内容适用于给定的测试数据：

(^|[^0-9])(0\.[1-9]|1\.0|1)($|[^0-9])

regex101 example here

Answer 3

鲍勃的答案是正确的，但是，可以做一些调整...

因此它与1. | .1不匹配
因此返回的捕获不包括\n
这样返回的匹配是一个单维数组

RegEx

(?<=^|[^[0-9]\.])(0\.[1-9]|1)(?=$|[^[0-9]\.])
(?<=                                            : Start of positive look behind
    ^                                           : Matches start of string
     |                                          : OR operator
      [^0-9\.]                                : Matches anything but 0-9 or literal "."
                )                               : End of look behind group
                 (                              : Start of capture group
                  0\.[1-9]                      : Matches 0.1 -> 0.9
                          |                     : OR operator
                           1                    : Matches 1 on it's own
                            )                   : End of capture group
                             (?=                : Start of positive look ahead
                                $               : Matches end of string
                                 |              : OR operator
                                  [^0-9\.]    : Matches anything BUT 0-9 or literal "."
                                            )   : End of look ahead

替代样式

还可以调整范围0-9：

[0-9] == \d

(?<=^|[^\d\.])(0\.[1-9]|1)(?=$|[^\d\.])

标志

您还需要实现几个RegEx标志：

g    : Global
m    : Multiline mode

JS示例

var data = `
0.1    : Match
1      : Match
0.111  : No-match
011.2  : No-match
1.2    : No-match
0.2    : Match
0      : No-match
0.1    : Match
.1     : No-match
1.0    : Match
`;

var re = /(?<=^|[^\d\.])(0\.[1-9]|1)(?=$|[^\d\.])/gm;

console.log(data.match(re));  // Output: ["0.1", "1", "0.2", "0.1"]

正则表达式范围，十进制0.1到1

3 个答案: