Java String contains() 方法 Java String类 contains() 方法用于判断字符串中是否包含指定的字符或字符串。 语法 public boolean contains(CharSequence chars) 参数 chars -- 要判断的字符或字符串。 返回值 如果包含指定的字符或字符串返回 true,否则返回 f
下面是一个使用contains方法判断字符串中是否包含某个字符的示例代码: Stringstr="Hello World";charch='o';if(str.contains(Character.toString(ch))){System.out.println("字符串中包含字符 "+ch);}else{System.out.println("字符串中不包含字符 "+ch);} 1. 2. 3. 4. 5. 6. 7. 8. 输出结果为:...
String.contains方法的签名如下: publicbooleancontains(CharSequencesequence) 1. 当调用此方法时,Java 会遍历原字符串的每一个字符并检查是否能够找到匹配的子字符串。这种实现方式虽然简单直观,但当字符串长度非常大、且进行多次查询时,性能可能会显著下降。 性能问题 以下是contains方法可能引发性能问题的一些情境: 大...
正文 1 可以使用String contains方法。java在contains（）方法是判断字符串中是否有子字符串。当且仅当此字符串包含指定的char值序列，如果有则返回true，如果没有则返回false。如：if(map_string.contains("name")){System.out.println("找到了name的key");}if(map_string.contains("password")){System.out.pri...
Write a Java program to compute the smallest window substring and handle cases when no valid window exists. Java Code Editor: Improve this sample solution and post your code through Disqus Previous:Write a Java program to match two strings where one string contains wildcard characters. ...
Home Question how to check if string contains '+' character You need this instead:if(s.contains("+")) contains() method of String class does not take regular expression as a parameter, it takes normal text.EDIT:String s = "ddjdjdj+kfkfkf"; if(s.contains("+")) { String parts[] ...
import java.lang.*; public class StringDemo { public static void main(String[] args) { String str1 = "tutorials point", str2 = "http://"; CharSequence cs1 = "int"; // string contains the specified sequence of char values boolean retval = str1.contains(cs1); ...
returns falseif the string doesn't contain the specified character Example 1: Java String contains() classMain{publicstaticvoidmain(String[] args){ String str1 ="Learn Java"; Boolean result;// check if str1 contains "Java"result = str1.contains("Java"); ...
import java.lang.*; public class StringDemo { public static void main(String[] args) { String str1 = "tutorials point", str2 = "http://"; CharSequence cs1 = "int"; // string contains the specified sequence of char values boolean retval = str1.contains(cs1); ...
ExampleGet your own Java Server Find out if a string contains a sequence of characters: StringmyStr="Hello";System.out.println(myStr.contains("Hel"));// trueSystem.out.println(myStr.contains("e"));// trueSystem.out.println(myStr.contains("Hi"));// false ...