
jshell&gt; x = 5
|  Error:
|  cannot find symbol
|    symbol:   variable x
|  x = 5
|  ^

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

jshell&gt; /vars
|    int x = 5

jshell&gt; double z = 4.56;
z ==&gt; 4.56

jshell&gt; float f = 4.5
|  Error:
|  incompatible types: possible lossy conversion from double to float
|  float f = 4.5;
|            ^-^

jshell&gt; float f = 4.5f;
f ==&gt; 4.5

jshell&gt; // double is a 64 bit double-precison IEEE 754 number

jshell&gt; // float is a 32 bit single-precison IEEE 754 number

jshell&gt; String s = "some string";
s ==&gt; "some string"

jshell&gt; /vars
|    int x = 5
|    double z = 4.56
|    float f = 4.5
|    String s = "some string"

jshell&gt; x += 1;
$5 ==&gt; 6

jshell&gt; x
x ==&gt; 6

jshell&gt; x++;   //does not exist in Python
$7 ==&gt; 6

jshell&gt; x
x ==&gt; 7

jshell&gt; $5
$5 ==&gt; 6

jshell&gt; $7
$7 ==&gt; 6

jshell&gt; x += 2
$11 ==&gt; 9

jshell&gt; x *= 2
$12 ==&gt; 18

jshell&gt; //compound assignment is the same

jshell&gt; 6/5
$13 ==&gt; 1

jshell&gt; double(6)/5
|  Error:
|  '.class' expected
|  double(6)/5
|        ^
|  Error:
|  unexpected type
|    required: value
|    found:    class
|  double(6)/5
|  ^----^

jshell&gt; (double) 6/5
$14 ==&gt; 1.2

jshell&gt; 365%7
$15 ==&gt; 1

jshell&gt; // ints:  + - * /(integer division)

jshell&gt; 5**3
|  Error:
|  illegal start of expression
|  5**3
|    ^

jshell&gt; Math.pow(5,3)
$16 ==&gt; 125.0

jshell&gt; Math.cos(0)
$17 ==&gt; 1.0

jshell&gt; int x = Math.factorial(5)
|  Error:
|  cannot find symbol
|    symbol:   method factorial(int)
|  int x = Math.factorial(5);
|          ^------------^

jshell&gt; Math.log(10)
$18 ==&gt; 2.302585092994046

jshell&gt; Math.log(10,10)
|  Error:
|  method log in class java.lang.Math cannot be applied to given types;
|    required: double
|    found:    int,int
|    reason: actual and formal argument lists differ in length
|  Math.log(10,10)
|  ^------^

jshell&gt; Math.log10(10)
$19 ==&gt; 1.0

jshell&gt; 4 &lt; 5
$20 ==&gt; true

jshell&gt; boolean b = 4 &lt; 5;
b ==&gt; true

jshell&gt; true &amp;&amp; true
$22 ==&gt; true

jshell&gt; //and

jshell&gt; true || true
$23 ==&gt; true

jshell&gt; // || is or

jshell&gt; 5&amp;7
$24 ==&gt; 5

jshell&gt; int n = 0;
n ==&gt; 0

jshell&gt; n = 1;
n ==&gt; 1

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

jshell&gt; n
n ==&gt; -2147483648

jshell&gt; n--;
$29 ==&gt; -2147483648

jshell&gt; n
n ==&gt; 2147483647

jshell&gt; //int is a 32 bit signed integer in two's complement notation

jshell&gt; byte b = 1
b ==&gt; 1

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

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

jshell&gt; short sh = 1
sh ==&gt; 1

jshell&gt; while(s &gt; 0){s++;}
|  Error:
|  bad operand types for binary operator '&gt;'
|    first type:  java.lang.String
|    second type: int
|  while(s &gt; 0){s++;}
|        ^---^
|  Error:
|  bad operand type java.lang.String for unary operator '++'
|  while(s &gt; 0){s++;}
|               ^-^

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

jshell&gt; sh
sh ==&gt; -32768

jshell&gt; //byte one-byte integer

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

jshell&gt; b = 300;
|  Error:
|  incompatible types: possible lossy conversion from int to byte
|  b = 300;
|      ^-^

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

jshell&gt; b = (byte) 300;
b ==&gt; 44

jshell&gt; long big = 1;
big ==&gt; 1

jshell&gt; for(int k = 0; k &lt; 30; k++){big *= 2;}

jshell&gt; big
big ==&gt; 1073741824

jshell&gt; for(int k = 0; k &lt; 30; k++){big *= 2;}

jshell&gt; big
big ==&gt; 1152921504606846976

jshell&gt; big *=2
$45 ==&gt; 2305843009213693952

jshell&gt; big *=2
$46 ==&gt; 4611686018427387904

jshell&gt; big *=2
$47 ==&gt; -9223372036854775808

jshell&gt; //long is a 64 bit integer.

jshell&gt; //byte, short, int, long.  integer types

jshell&gt; //boolean: true, false

jshell&gt; //floatingpoint:  float, double

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

jshell&gt; (int) q
$49 ==&gt; 97

jshell&gt; (char) 65
$50 ==&gt; 'A'

jshell&gt;