剑指Offre 面试题05. 替换空格

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
 * @Auther: truedei
 * @Date: 2020 /20-5-6 22:46
 * @Description:
 */
public class TestA {
    static public String replaceSpace(String s) {
        //1693648纳秒
        return s.replaceAll("[ ]", "%20");
        //1355205纳秒
        return s.replace(" ","%20");
        //636976纳秒
        StringBuilder s1 = new StringBuilder();
        for (int i = 0; i < s.length(); i++) {
            if(s.charAt(i)==(char)' '){
                s1.append("%20");
            }else {
                s1.append(s.charAt(i));
            }
        }
        return s1.toString();
        //594273纳秒
        String s1="";
        for (int i = 0; i < s.length(); i++) {
            if(s.charAt(i)==(char)' '){
                s1=s1+"%20";
            }else {
                s1=s1+s.charAt(i);
            }
        }
        return s1;
    }
}