Java 整数或双精度的正则表达式
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regex for integer or double
提问by
There is a string "12.2A12W99.0Z0.123Q9"
I need to find 3 groups: (double or int)(nondigit)(double or int)
So in the case of the sample, I would want this to happen:
matcher.group (1) = "12.2"
matcher.group (2) = "A"
matcher.group (3) = "12"
有一个字符串 "12.2A12W99.0Z0.123Q9" 我需要找到 3 个组：(double or int)(nondigit)(double or int) 所以在示例的情况下，我希望这种情况发生：
matcher.group (1) = "12.2"
matcher.group (2) = "A"
matcher.group (3) = "12"
My current regex only matches against integers: "^(\d+)(\D)(\d+)" So I am looking to change the group (\d+) to something that will match against integers OR doubles.
我当前的正则表达式只与整数匹配：“^(\d+)(\D)(\d+)”所以我希望将组 (\d+) 更改为与整数匹配或加倍的内容。
I dont understand regex at all, so explaining like I'm 5 would be cool.
我根本不懂正则表达式，所以像我 5 岁那样解释会很酷。
回答by Yogesh Tatwal
try below code :- Your regular expression is only matching numeric characters. To also match the decimal point too you will need:
尝试以下代码：-您的正则表达式仅匹配数字字符。要也匹配小数点，您将需要：
Pattern.compile("\d+\.\d+")
private Pattern p = Pattern.compile("\d+(\.\d+)?");
The . is escaped because this would match any character when unescaped.
这 。被转义，因为这在未转义时将匹配任何字符。
Note: this will then only match numbers with a decimal point which is what you have in your example.
注意：这将只匹配带有小数点的数字，这就是您在示例中所拥有的。
private Pattern p = Pattern.compile("\d+(\.\d+)?");
public void testInteger() {
Matcher m =p.matcher("10");
assertTrue(m.find());
assertEquals("10", m.group());
}
public void testDecimal() {
Matcher m =p.matcher("10.99");
assertTrue(m.find());
assertEquals("10.99", m.group());
}
