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 theStringclass in Java. We will learn about each method with help of small code examples for better understanding. 下面指定的方法是Java中String类最常用的方法。 我...
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...
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";
Let us start with getting the first character of the string, i.e. the character at the index position 0. Stringstr="howtodoinjava.com";Assertions.assertEquals('h',str.charAt(0)); To get the last character of theString, use theString.length()and subtract 1 to get the last valid index...
java Charater类 Java 编译器 转载 码海舵手之心 7月前 15阅读 前端charAt函数 前端的charAt()函数用于返回一个字符串中指定位置的字符。该函数的语法如下:string.charAt(index)其中,string 是要操作的字符串,index 是字符的位置,从 0 开始计数。以下是一个示例:var str = "Hello World"; var char = str....
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.StringIndexOutOf...
ExampleGet your own Java Server Return the first character (0) of a string: String myStr = "Hello"; char result = myStr.charAt(0); System.out.println(result); Try it Yourself » Definition and UsageThe charAt() method returns the character at the specified index in a string....
(21); char i=test.charAt(-1); System.out.println(i); } } 异常信息 20 Exception in thread "main..." java.lang.StringIndexOutOfBoundsException: String index out of range: -1 at java.lang.String.charAt...个人总结: 如果程序中出现StringIndexOutOfBoundsException,表示程序尝试获取大于等于字符...
字符串的比较、字符串的拼接、字符串的截取、字符串的修改以及字符串的转换。此外，还介绍了Java中字符...
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();...