//5种构造方法
public void Con(){
String str = "sfaj";
String str1 = new String("sfajdf");
String str2 = new String();
str2 = "sfaj";
char[] cArr = {\'s\',\'f\',\'a\',\'d\',\'f\',\'j\'};
String str3 = new String();
String str4 = new String(cArr,0,2);
}
public void pra(){
String str = new String("sfajdfjal;fjje23jkdjfa jdkf");
//equals:相等
System.out.println(str.equals("dddd"));
//startsWith() && endsWith();
System.out.println(str.startsWith("sfa"));
System.out.println(str.endsWith("kf"));
//compareTo()
System.out.println("ac".compareTo("ad"));
System.out.println("ac".compareTo("af"));
}
@Test
public void prac(){//
String str = new String("sfajdfjal;fjje23jkdjfa jdkf");
//indexOf();
System.out.println(str.indexOf("s"));
System.out.println(str.indexOf("f", 7));
//lastIndexOf(str);lastIndexOf(str,int end)
System.out.println(str.lastIndexOf("j"));
System.out.println(str.lastIndexOf("j",10));
//subString(int start);subString(int start,int end) start开始，end以前
System.out.println(str.substring(20));
System.out.println(str.substring(10,14));
}
public void pract(){
String str = new String(" sfajdfjal;fjje23jkdjfa jdkf ");
//replaceAll(str,str1);
String str2 = str.replace("f", "哒哒哒");
System.out.println(str2);
//trim：去除前后的空格
String str3 = str.trim();
System.out.println(str3);
//split();拆分
String[] str4 = str.split("f");
for(String s : str4){
System.out.println(s);
}
}