定义一个String s=”hello,everyone,welcome to learn java!” 完成题目: 1 统计字符的个数 2 求出welcome的起始索引,并输出welcome单词 3 按逗号拆分成一个数组,并输出数组内容 4 将字符串的everyone改成单词students,并输出。 5 键盘输入一句英语句子,提取输出句子中的单词
时间: 2023-05-29 16:07:32 浏览: 39
1. 统计字符的个数
```java
String s = "hello,everyone,welcome to learn java!";
int count = s.length();
System.out.println("字符个数为:" + count);
```
输出结果为:字符个数为:39
2. 求出welcome的起始索引,并输出welcome单词
```java
String s = "hello,everyone,welcome to learn java!";
int index = s.indexOf("welcome");
System.out.println("welcome的起始索引为:" + index);
System.out.println("welcome单词为:" + s.substring(index, index + 7));
```
输出结果为:welcome的起始索引为:14,welcome单词为:welcome
3. 按逗号拆分成一个数组,并输出数组内容
```java
String s = "hello,everyone,welcome to learn java!";
String[] arr = s.split(",");
System.out.println("数组内容为:");
for (String str : arr) {
System.out.println(str);
}
```
输出结果为:
数组内容为:
hello
everyone
welcome to learn java!
4. 将字符串的everyone改成单词students,并输出
```java
String s = "hello,everyone,welcome to learn java!";
s = s.replace("everyone", "students");
System.out.println("替换后的字符串为:" + s);
```
输出结果为:替换后的字符串为:hello,students,welcome to learn java!
5. 键盘输入一句英语句子,提取输出句子中的单词
```java
Scanner sc = new Scanner(System.in);
System.out.println("请输入句子:");
String sentence = sc.nextLine();
String[] words = sentence.split(" ");
System.out.println("句子中的单词为:");
for (String word : words) {
System.out.println(word);
}
```
输入示例:This is a test sentence.
输出结果为:
句子中的单词为:
This
is
a
test
sentence.