(base) MAC:Thu Oct 15:11:08:Desktop> vi Foo.java
(base) MAC:Thu Oct 15:11:08:Desktop> jshell
|  Welcome to JShell -- Version 14.0.1
|  For an introduction type: /help intro

jshell> /open Foo.java

jshell> f
|  Error:
|  cannot find symbol
|    symbol:   variable f
|  f
|  ^

jshell> Foo f = new Foo();
f ==> Foo@31cefde0

jshell> f.hashCode()
$3 ==> 835648992

jshell> Integer.toString(f.hashCode(), 16)
$4 ==> "31cefde0"

jshell> "a".hashCode()
$5 ==> 97

jshell> "abc".hashCode()
$6 ==> 96354

jshell> String s = "some";
s ==> "some"

jshell> String t = "thing";
t ==> "thing"

jshell> s + t
$9 ==> "something"

jshell> s*50
|  Error:
|  bad operand types for binary operator '*'
|    first type:  java.lang.String
|    second type: int
|  s*50
|  ^--^

jshell> s.repeat(50)
$10 ==> "somesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesomesome"

jshell> s[0]
|  Error:
|  array required, but java.lang.String found
|  s[0]
|  ^--^

jshell> s.charAt(0)
$11 ==> 's'

jshell> s.concat(t)
$12 ==> "something"

jshell> s.charAt(45)
|  Exception java.lang.StringIndexOutOfBoundsException: String index out of range: 45
|        at StringLatin1.charAt (StringLatin1.java:48)
|        at String.charAt (String.java:711)
|        at (#13:1)

jshell> s < t
|  Error:
|  bad operand types for binary operator '<'
|    first type:  java.lang.String
|    second type: java.lang.String
|  s < t
|  ^---^

jshell> s.compareTo(t)
$14 ==> -1

jshell> s.compareTo(t) < 0
$15 ==> true

jshell> s.comparetTo(t) > 0
|  Error:
|  cannot find symbol
|    symbol:   method comparetTo(java.lang.String)
|  s.comparetTo(t) > 0
|  ^----------^

jshell> s.compareTo(t) > 0
$16 ==> false

jshell> "a".compareTo("z")
$17 ==> -25

jshell> (int)'a'
$18 ==> 97

jshell> (int)'z'
$19 ==> 122

jshell> "abby".compareTo("acid")
$20 ==> -1

jshell> "abby".comparetTo("acid") < 0   // "abby" < "acid"  (python)
|  Error:
|  cannot find symbol
|    symbol:   method comparetTo(java.lang.String)
|  "abby".comparetTo("acid") < 0   // "abby" < "acid"  (python)
|  ^---------------^

jshell> "abby".compareTo("acid") < 0   // "abby" < "acid"  (python)
$21 ==> true

jshell> "abby".compareTo("acid") > 0   // "abby" > "acid"  (python)
$22 ==> false

jshell> "abby".compareTo("ACID") < 0
$23 ==> false

jshell> "abby".compareToIgnoreCase("ACID") < 0
$24 ==> true

jshell> "catamaran".contains("tamar")
$25 ==> true

jshell> // "tamar" in "catamaran"

jshell> "dumbo.html".endsWith(".html")
$26 ==> true

jshell> "dumbo.html".startsWith("dumbo")
$27 ==> true

jshell> String s = "noodle"
s ==> "noodle"

jshell> String t = "noodle"
t ==> "noodle"

jshell> s.equals(t)
$30 ==> true

jshell> s == t
$31 ==> true

jshell> String.format("(%s, %s)", 5,6);
$32 ==> "(5, 6)"

jshell> "" + 5
$33 ==> "5"

jshell> "" + 5 + 4.6 + "cat"
$34 ==> "54.6cat"

jshell> "" + (5 + 4.6) + "cat"
$35 ==> "9.6cat"

jshell> string s = "abcdefghijklmnop"
|  Error:
|  cannot find symbol
|    symbol:   class string
|  string s = "abcdefghijklmnop";
|  ^----^

jshell> String s = "abcdefghijklmnop"
s ==> "abcdefghijklmnop"

jshell> s.indexOf('c')
$37 ==> 2

jshell> s.indexOf('c', 6)
$38 ==> -1

jshell> s.indexOf("jkl")
$39 ==> 9

jshell> s.indexOf("jkl", 7)
$40 ==> 9

jshell> s.indexOf("jkl", 11)
$41 ==> -1

jshell> s.isBlank()
$42 ==> false

jshell> String w = "     \t\t\t\t\n\n   "
w ==> "     \t\t\t\t\n\n   "

jshell> w.isBlank()
$44 ==> true

jshell> s.length()
$45 ==> 16

jshell> s.repeat(4)
$46 ==> "abcdefghijklmnopabcdefghijklmnopabcdefghijklmnopabcdefghijklmnop"

jshell> "*".repeat(50)
$47 ==> "**************************************************"

jshell> x = "     space      "
|  Error:
|  cannot find symbol
|    symbol:   variable x
|  x = "     space      "
|  ^

jshell> String x = "     space      "
x ==> "     space      "

jshell> x.strip()
$49 ==> "space"

jshell> s.lstrip()
|  Error:
|  cannot find symbol
|    symbol:   method lstrip()
|  s.lstrip()
|  ^------^

jshell> s.stripLeading()
$50 ==> "abcdefghijklmnop"

jshell> //lstrip()

jshell> s.stripTrailing()
$51 ==> "abcdefghijklmnop"

jshell> //rstrip

jshell> s
s ==> "abcdefghijklmnop"

jshell> s.substring(5)
$53 ==> "fghijklmnop"

jshell> // s[5:]

jshell> s.substring(2,5)
$54 ==> "cde"

jshell> //s[2:5]

jshell> s.substring(0,3)
$55 ==> "abc"

jshell> //s[:3]

jshell> s.toUpperCase()
$56 ==> "ABCDEFGHIJKLMNOP"

jshell> s.toLowerCase()
$57 ==> "abcdefghijklmnop"

jshell> s.SwapCase()
|  Error:
|  cannot find symbol
|    symbol:   method SwapCase()
|  s.SwapCase()
|  ^--------^

jshell> s.swapCase()
|  Error:
|  cannot find symbol
|    symbol:   method swapCase()
|  s.swapCase()
|  ^--------^

jshell> s
s ==> "abcdefghijklmnop"

jshell> s.replace("a", "A")
$59 ==> "Abcdefghijklmnop"

jshell> s
s ==> "abcdefghijklmnop"

jshell> s.replace("klmn", "cows")
$61 ==> "abcdefghijcowsop"

jshell> s.replace("c", "C");
$62 ==> "abCdefghijklmnop"

jshell> s.replace("klmn", "cows").replace("c", "C")
$63 ==> "abCdefghijCowsop"

jshell> s.toUpperCase()
$64 ==> "ABCDEFGHIJKLMNOP"

jshell> String.valueOf(true)
$65 ==> "true"

jshell> String.valueOf(false)
$66 ==> "false"

jshell> String.valueOf(45)
$67 ==> "45"

jshell> String.valueOf(6.02e23)
$68 ==> "6.02E23"

jshell> byte b = 5
b ==> 5

jshell> String.valueOf(b)
$70 ==> "5"

jshell> int k = 5
k ==> 5

jshell> "" + k
$72 ==> "5"

jshell> Integer.toString(k)
$73 ==> "5"

jshell>