(base) MAC:Mon Oct 12:09:57:~&gt; jshell
|  Welcome to JShell -- Version 14.0.1
|  For an introduction type: /help intro

jshell&gt; int x = 5;
x ==&gt; 5

jshell&gt; x = "cowabunga"
|  Error:
|  incompatible types: java.lang.String cannot be converted to int
|  x = "cowabunga"
|      ^---------^

jshell&gt; x += 4;
$2 ==&gt; 9

jshell&gt; //compound assignment and assignment: just like Py

jshell&gt; //once a variable has a type, it cannot be changed.

jshell&gt; 4*5
$3 ==&gt; 20

jshell&gt; 4 + 5
$4 ==&gt; 9

jshell&gt; 4 - 5
$5 ==&gt; -1

jshell&gt; 4/5
$6 ==&gt; 0

jshell&gt; 4%5
$7 ==&gt; 4

jshell&gt; 4**5
|  Error:
|  illegal start of expression
|  4**5
|    ^

jshell&gt; // you got POW for using pow.

jshell&gt; Math.pow(4,5)
$8 ==&gt; 1024.0

jshell&gt; pow(4,5)
|  Error:
|  cannot find symbol
|    symbol:   method pow(int,int)
|  pow(4,5)
|  ^-^

jshell&gt; byte b = 6;
b ==&gt; 6

jshell&gt; while(b &gt; 0){ b++;}

jshell&gt; b
b ==&gt; -128

jshell&gt; b--;
$12 ==&gt; -128

jshell&gt; b
b ==&gt; 127

jshell&gt; short s = 0;
s ==&gt; 0

jshell&gt; s
s ==&gt; 0

jshell&gt; while(s &gt;= 0){s++;}

jshell&gt; s
s ==&gt; -32768

jshell&gt; s--;
$19 ==&gt; -32768

jshell&gt; s
s ==&gt; 32767

jshell&gt; int i = 0;
i ==&gt; 0

jshell&gt; while(i &gt;= 0){i++;}

jshell&gt; i
i ==&gt; -2147483648

jshell&gt; i--;
$24 ==&gt; -2147483648

jshell&gt; i
i ==&gt; 2147483647

jshell&gt; long i = 0;
i ==&gt; 0

jshell&gt; Long.MAX_VALUE
$27 ==&gt; 9223372036854775807

jshell&gt; Long.MIN_VALUE
$28 ==&gt; -9223372036854775808

jshell&gt; Math.PI
$29 ==&gt; 3.141592653589793

jshell&gt; double x = 5.6;
x ==&gt; 5.6

jshell&gt; (int) x
$31 ==&gt; 5

jshell&gt; (double) 4
$32 ==&gt; 4.0

jshell&gt; (boolean) 5
|  Error:
|  incompatible types: int cannot be converted to boolean
|  (boolean) 5
|            ^

jshell&gt; true
$33 ==&gt; true

jshell&gt; false
$34 ==&gt; false

jshell&gt; 4 &lt; 5
$35 ==&gt; true

jshell&gt; // &lt; &lt;= &gt;= &gt; == !=

jshell&gt; // These are the relational operators.

jshell&gt; char c = 'a
|  Error:
|  unclosed character literal
|  char c = 'a
|           ^

jshell&gt; char c = 'a'
c ==&gt; 'a'

jshell&gt; (int) c
$37 ==&gt; 97

jshell&gt; (char) 945
$38 ==&gt; 'α'

jshell&gt; String foo = "bar";
foo ==&gt; "bar"

jshell&gt; /exit
|  Goodbye
(base) MAC:Mon Oct 12:10:17:~&gt;