知道字符串的长度

public class Main {

  public static void main (String[] args) {

    // Create two string objects 
    /** 
    来 自 
    n o w j a   v  a . c o m - 时  代  Java
    **/

    String str1 = new String() ;

    String str2 = new String("Hello") ;


    // Get the length of str1 and str2 

    int len1 = str1.length();

    int len2 = str2.length();


    // Display the length of str1 and str2 

    System.out.println("Length of \"" + str1 + "\" = " + len1);
    /*
    来 自*