2017-01-09上午看了点儿面试的东西 感觉东西还行

package day14;

public class StringDemo01 {

/*public static void main(String[] args) {
String i="";
if(i==i+0){
System.out.println("hello world");
}else{
System.out.println("123");
}
}*/

/*public static void main(String []args){
String s1 = new String("a").intern();
s1.intern();
String s2 = "a";
System.out.println(s1==s2);
}*/

/*public static void main(String []args){
String string="ABCDEFGH";
String string2=string.substring(3,5); //[3,5)
System.out.println(string2);
}*/

/*public static void main(String []args){
String string1="hello";
String string2=new String("hello");
string2=string2.intern();
System.out.println(string1==string2);
}*/

//会产生大量的存储浪费
/*public static void main(String []args){
String tmp="";
for(int i=0;i<9999;i++){
tmp+="x";
}
}*/

/*public static void main(String []args){
String A,B,C;
A="a";
B="b";
C=A+B;
StringBuffer D=new StringBuffer("abc");
D=D.append("567");
}
*/

//正则表达式01
/*public static void main(String []args){
String string="32132131231dfafdaf0fasfsa1fsdafdsaf";
string=string.replaceAll("[^0-9]", "");
System.out.println(string);
}*/

/*public static void main(String []args){
String string="2017-01-09 10:38:55";
string=string.replace("-", "");
string=string.replace(":", "");
string=string.replace(" ", "");
System.out.println(string);
}*/

/*public static void main(String []args){
String string="2017-01-09 10:38:55";
String str2="";
String []result=string.split("\\d");
for(int i=0;i<result.length;i++){
//System.out.print(result[i]+" ");
str2+=result[i];
}
System.out.println(str2);
}
*/

}