零宽断言
package org.zly;
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public class Main1 {
public static void main(String[] args) {
/** 匹配前面不是456的asd **/
String str = "123asd456asd789asd";
System.out.println(str.replaceAll("(?<!456)asd", ""));
/** 匹配后面不是456的asd **/
String str1 = "asd123asd456asd789";
System.out.println(str1.replaceAll("asd(?!456)", ""));
/** 匹配后面是456的asd **/
String str2 = "asd123asd456asd789";
System.out.println(str2.replaceAll("asd(?=456)", ""));
/** 匹配前面是456的asd **/
String str3 = "123asd456asd789asd";
System.out.println(str3.replaceAll("(?<=456)asd", ""));
}
}
