!10//give the vector 1..10
1 2 3 4 5 6 7 8 9 10

100*!10//multiply that vector by 100
100 200 300 400 500 600 700 800 900 1000

3 4#!10//reshape the vector 1..10 into a 3x4 matrix
1  2 3 4
5  6 7 8
9 10 1 2

&.3 4#!10//flip the above matrix
1 5  9
2 6 10
3 7  1
4 8  2

+/3 4#!10//sum each row of the 3x4 matrix
10 26 22

2*0,!10//append 0 in front of 1..10, and double it
0 2 4 6 8 10 12 14 16 18 20

2*.0,!10//2 to the power of 0..10
1 2 4 8 16 32 64 128 256 512 1024

%1 2 3 5 10//1 divided by 1 2 3 5 10
1 0.5 0.3333333333 0.2 0.1

1024*.%1 2 3 5 10//1024 takes 1 root, square root, cube root, …
1024 32 10.0793684 4 2

1-2//1 minus 2
_1

_1*.0.5//square root of minus 1
0j1

@1//pi
3.141592654

*.0j1*@1//e^iΠ = -1
_1

2012.12.25+!7//7 days following Christmas of 2012
2012.12.26 2012.12.27 2012.12.28 2012.12.29 2012.12.30 2012.12.31 2013.01.01

w<-10?.100//get 10 random numbers from 1..100
    w
14 76 46 54 22 5 68 94 39 52

(w<50)/w//get those in w which is less than 50
14 46 22 5 39

y<-12+2*!7
y
14 16 18 20 22 24 26

(~w?y)/w//get those in w which are not in y
76 46 54 5 68 94 39 52

+/(~w?y)/w//get total sum of those left
434

$_5+!15//reverse of _5 adds to 1..15
10 9 8 7 6 5 4 3 2 1 0 _1 _2 _3 _4

32+1.8*c<-$_5+!15//Fahrenheit correspond to Celsius above
50 48.2 46.4 44.6 42.8 41 39.2 37.4 35.6 33.8 32 30.2 28.4 26.6 24.8

c,[1.5]32+1.8*c<-$_5+!15  //a table of temperature conversion
10 50  
 9 48.2
 8 46.4
 7 44.6
 6 42.8
 5 41  
 4 39.2
 3 37.4
 2 35.6
 1 33.8
 0 32  
_1 30.2
_2 28.4
_3 26.6
_4 24.8