java - 使用包含方法时如何使 IgnoreCase

Question

这个问题已经有答案了:

How to check if a String contains another String in a case insensitive manner in Java? (20 个回答)

String contains - ignore case [duplicate] (5 个回答)

已关闭 8 年前。

我试图让它在使用包含方法时忽略大小写。我该怎么做？

String text = "Did you eat yet?";   

if(text.contains("eat") && text.contains("yet"))
    System.out.println("Yes");
else
    System.out.println("No.");

Answer 1

不幸的是，String 没有 String.containsIgnoreCase 方法。

但是，您可以使用正则表达式验证类似的条件。

例如:

String text = "Did you eat yet?";
// will match a String containing both words "eat", 
// then "yet" in that order of appearance, case-insensitive
//                           | word boundary
//                           |        | any character, zero or more times 
Pattern p = Pattern.compile("\\beat\\b.*\\byet\\b", Pattern.CASE_INSENSITIVE);
Matcher m = p.matcher(text);
System.out.println(m.find());

简单版本(感谢 blgt ):

// here we match the whole String, so we need start-of-input and 
// end-of-input delimiters
//                               | case-insensitive flag
//                               |   | beginning of input
//                               |   |                        | end of input
System.out.println(text.matches("(?i)^.*\\beat\\b.*\\byet\\b.*$"));

输出

true