Chapter 2 Basic Operations

2.1 Arithmetic and Variables

• Basic arithmetic: + - * %

  q)21+33
  54
  q)11-5
  6
  q)7*7
  49
  q)12%2
  6f /the "f" denotes that the number is a float

• Right to left execution

  q)5*2+3
  25

• Use brackets as precedence

  q)(5*2)+3
  13

• Comments can be made after a ’/’ :

  q)a:1 /this is a comment
  q)a
  1

• Assign variables using ‘:’ instead of ‘=’

  q)a:2
  q)b:3
  q)c:4
  q)d:a*b*c
  q)d
  24

• ‘=’ is used for comparison

  q)a:2
  q)b:3
  q)3=2
  0b /indicating that the statement 'a equals b' is false
  q)5.0=5

• Comparison can be:

  >= /Greater than or equal to
  > /Greater than
  <= /Less than or equal to
  < /Less than
  = /Equal
  <> /Not equal
  ~ /Match - examined in the next section

• For example:

  q)4>1
  1b
  q)10<>4
  1b
  q)8>=8
  1b
  q)6<=3

• Assignments can be combined in a single operation:

  q)x:10
  q)x:x+1
  q)x
  11
  q)x+:1
  12
  q)x*:3
  q)x
  36

• Multi-assignment can be performed on one line:

  q)c:1+b:3*a:2
  q)a
  2
  q)b
  6
  q)c

• Use nv to check variable names:

  q)\v
  `a`b`c`d`x