String s ="abcd"; System.out.println(s.contains('a')); 1. 2. 会报语法错误:The method contains(CharSequence) in the type String is not applicable for the arguments (char)。参数类型不匹配。 打开api我们看到CharSequence是一个interface,所以我们没法直接用它的对象,只能用它的实现类的对象,它有几个实现类String,StringBuilder等,所以我们这里传入S...
Example 1: Java String contains() classMain{publicstaticvoidmain(String[] args){ String str1 ="Learn Java"; Boolean result;// check if str1 contains "Java"result = str1.contains("Java"); System.out.println(result);// true// check if str1 contains "Python"result = str1.contains("Py...
String[]arr={"apple","banana","orange"};if(!Arrays.asList(arr).contains("pear")){System.out.println("pear is not in the array");} 1. 2. 3. 4. 5. 上述代码会输出"pear is not in the array",这符合我们的预期。我们使用Arrays.asList方法将字符串数组转换为ArrayList,然后使用contains方法...
Returns:Aboolean, indicating whether a sequence of characters exist in the specified string: true- sequence of characters exists false- sequence of characters do not exist Throws:NullPointerException- if the returned value is null Java Version:1.5 ...
alphabet = 'abcdefghijklmnopqrstuvwxyz' contains_a = 'a' in alphabet # True contains_z = 'z' in alphabet # True does_not_contain_1 = '1' in alphabet # False Java 代码语言:txt 复制 String alphabet = "abcdefghijklmnopqrstuvwxyz"; boolean containsA = alphabet.contains("a"); // tr...
Java String.contains() searches case-sensitive substring in a given string. It returns true if the substring is found, otherwise false.
1:Scanner的使用(了解) (1)在JDK5以后出现的用于键盘录入数据的类。 (2)构造方法: A:讲解了System.in这个东西。 它其实是标准的输入流,对应于键盘录入 B:构造方法 InputStream is = System.in; Scanner(InputStream is) C
true if this string containss, false otherwise Attributes RegisterAttribute Remarks Returns true if and only if this string contains the specified sequence of char values. Added in 1.5. Java documentation forjava.lang.String.contains(java.lang.CharSequence). ...
indexOf(String str)和contains(String str) 这两个什么异同? indexOf(String str)返回字符串在字符串对象中首次出现的索引,indexOf会返回该字符串在某字符串中的索引值,如果不存在则返回-1 contains(String str)是在当前字符串中 查找是否包含指定字符串,String的contains,如果包含则返回true,否则返回false...
所谓“常用场景”，Java里大多数String的长度其实并不长。有兴趣的话可以跑一个您的应用场景里的典型...