public static void main(String[] args) { String str = "Hello, World!"; char ch = str.charAt(4); System.out.println(ch); // Output: o } } 在这个例子中,我们创建了一个字符串`"Hello, World!"`,然后调用了`charAt()`方法来获取该字符串中位置为4的字符,即`o`。最后,使用`System.out.p...
String str = "Hello, World!"; char ch = str.charAt(0); // 获取第一个字符 ch = Character.toUpperCase(ch); // 将其转换为大写 System.out.println("First character in uppercase: " + ch); 复制代码 然而,charAt() 函数也有一些限制: 索引越界:如果传递给 charAt() 函数的索引超出了字符串的...
out.println("The fifth character is: " + fifthChar); // 获取索引为-1的字符(这将抛出StringIndexOutOfBoundsException异常) char invalidChar = str.charAt(-1); } } 复制代码 输出: The first character is: H The fifth character is: o Exception in thread "main" java.lang.StringIndexOutOfBoun...
StringCharAt extends StringOperator implements BinaryOperator Implementation of the StringCharAt operator. Input 1: A String (or Expression returning a String) that is LHS of the operator. Input 2: A Number (or Expression returning a Number) that is RHS of the operator. Returns: A Character:...
output= "- exists in the first index of the String"; } else { output="- doesn't exists in the first index of the String"; } System.out.println(output); 它检查该 char 是否存在于索引 0 中,这是一个比较。 至于if (c < '9'),比较的是c和9的ascii值。我不知道你为什么要检查 c 的 ...
Java String.charAt() returns the character at specified index argument in the string object or literal. The argument must be a valid index.
charAt(int index) description of charAt returns char value at the specified index of string. example of charAt in java package lang; public class Lang { public static void main(String[] args) { String str = "test 1234";
charAt和String的用法 package charpter2; import java.util.Scanner; public class Test { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("请输入您想输入的内容:"); /*int num = sc.nextInt();...
import java.util.*; public class one { public static void main(String[] args) { String x=null; Scanner cin=new Scanner(System.in); int p=cin.nextInt(); int y; if (p==1)x="ll"; if (x==null||x.equals("")) y=100; ...
charAt java string 函数 java string的函数 string函数 java The methods specified below are some of the most commonly used methods of the String class in Java. We will learn about each method with help of small code examples for better understand 字符串 java python 正则表达式 mysql 转载 ...