JHTP自测题_第十四章_字符串、字符及正则表达式（Strings, Characters and Regular Expressions）

Self-Review Exercises

14.1
State whethereach of the following is
true
or
false. If
false, explain why.

a) When
String
objects arecompared using
==, the result is
true
if the
Strings contain thesame values. (False，String objects are compared using operator == to determine
whether they’re the same object in memory.)

b) A
String
can bemodified after it’s created. (False，String objects are immutable and cannot be modified after they’re created.

StringBuilder objects can be modified after they’re created.)

14.2
For each ofthe following, write a single statement that performs the indicated task:

a) Compare the string in
s1
to the stringin
s2
for equality of contents. (s1.equals(s2))

b) Append the string
s2
to the strings1,
using +=. (s1+=s2)

c) Determine the length of the string in
s1. 
(s1.length())