String常用API

package string;

public class Demo3 {
public static void main(String[] args) {
String str = “这是一个字符串abc”;
//获取字符串的长度
System.out.println(str.length());
//获取某个索引位置的字符
char c = str.charAt(1);
System.out.println©;
//遍历每个字符
for (int i = 0; i < str.length(); i++) {
char c1 = str.charAt(i);
System.out.print(c1);
}
System.out.println("\t");
//把字符串转化为字符数组
char[] chars = str.toCharArray();
for (int i = 0; i < chars.length; i++) {
char c2 = chars[i];
System.out.print(c2);
}
System.out.println("\t");
//截取内容，含头不含尾！
String str1 = “这是另一个字符串123”;
String substring = str1.substring(0, 8);
System.out.println(substring);
//从头到尾
System.out.println(str1.substring(8));
//替换
String str3 = “这是一个rnm，一个包含rnm的字符串”;
String s = str3.replace(“rnm”, “***”);
System.out.println(s);
//判断是否包含某字符
boolean b = str3.contains(“rnm”);
System.out.println(b);
//判断是以什么开始的
System.out.println(str1.startsWith(“这是”));
//按照某个内容把字符串分割成字符串数组返回
String str4 = “a,b,c”;
String[] s2 = str4.split(",");
for (int i = 0; i < s2.length; i++) {
System.out.println(“结果是”+s2[i]);
}
}
}