正则表达式验证中的十进制或数值 [英] Decimal or numeric values in regular expression validation
问题描述
我正在尝试使用正则表达式验证来仅检查十进制值或数值.但是用户输入的数值，不是第一个数字0"
I am trying to use a regular expression validation to check for only decimal values or numeric values. But user enters numeric value, it don't be first digit "0"
我该怎么做?
推荐答案
1-9 范围内的数字后跟零个或多个其他数字:
A digit in the range 1-9 followed by zero or more other digits:
^[1-9]\d*$
允许带有可选小数点后跟数字的数字.1-9 范围内的数字后跟零个或多个其他数字，然后可选地后跟小数点后跟至少 1 位数字:
To allow numbers with an optional decimal point followed by digits. A digit in the range 1-9 followed by zero or more other digits then optionally followed by a decimal point followed by at least 1 digit:
^[1-9]\d*(\.\d+)?$
注意事项:
^和$锚定开始和结束基本上是说整个字符串必须匹配模式
The
^and$anchor to the start and end basically saying that the whole string must match the pattern
()? 匹配括号内的整个事物的 0 或 1
()? matches 0 or 1 of the whole thing between the brackets
更新以处理逗号:
在正则表达式中 . 有一个特殊的含义——匹配任何单个字符.要逐字匹配字符串中的 .，您需要使用 \. 转义 . 这就是上面正则表达式中的 \. .因此，如果您想使用逗号，则模式很简单:
In regular expressions . has a special meaning - match any single character. To match literally a . in a string you need to escape the . using \. This is the meaning of the \. in the regexp above. So if you want to use comma instead the pattern is simply:
^[1-9]\d*(,\d+)?$
进一步更新以处理逗号和句号
如果您想在数字组之间允许 . 和在整数部分和小数部分之间允许 , ，请尝试:
If you want to allow a . between groups of digits and a , between the integral and the fractional parts then try:
^[1-9]\d{0,2}(\.\d{3})*(,\d+)?$
即这是一个 1-9 范围内的数字，后跟最多 2 个其他数字，然后是零组或多组句号，后跟 3 位数字，然后是可选的逗号和数字.
i.e. this is a digit in the range 1-9 followed by up to 2 other digits then zero or more groups of a full stop followed by 3 digits then optionally your comma and digits as before.
如果您想在数字之间的任何位置允许 . ，请尝试:
If you want to allow a . anywhere between the digits then try:
^[1-9][\.\d]*(,\d+)?$
即数字 1-9 后跟零个或多个数字或句号，可选后跟逗号和一个或多个数字.
i.e. a digit 1-9 followed by zero or more digits or full stops optionally followed by a comma and one or more digits.
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