Macaulay2 » Documentation
Packages » Macaulay2Doc » The Macaulay2 language » Thing » Nothing » null
next | previous | forward | backward | up | index | toc

# null -- the unique member of the empty class

## Description

When it is the value of an expression entered into the interpreter, the output line doesn't appear. Empty spots in a list are represented by it.

It is the only member of the class Nothing, which strictly speaking, ought to have no members at all.

An if expression with no else clause returns null when the predicate is false.

Various routines that prepare data for printing convert null to an empty string.

    i1 : x = {2,3,,4}

    o1 = {2, 3, , 4}

    o1 : List

    i2 : net x

    o2 = {2, 3, , 4}

    i3 : toString x#2

    o3 = null

    i4 : peek x

    o4 = {2, 3, null, 4}

## For the programmer

The object null is null.

The source of this document is in /build/macaulay2-88fgJW/macaulay2-1.25.11+ds/M2/Macaulay2/packages/Macaulay2Doc/ov_types.m2:575:0.