N_ELEMENTS Function

Reference Guide > M–N Routines > N_ELEMENTS Function

N_ELEMENTS Function

Returns the number of elements contained in any expression or variable.

Usage

result = N_ELEMENTS(expr)

Input Parameters

expr—The expression for which the number of elements will be returned.

Returned Value

result—The number of elements contained in any expression or variable.

Scalar expressions always have one element. The number of elements in an array is equal to the product of its dimensions. If expr is an undefined variable, N_ELEMENTS will return zero.

Keywords

None.

Example

In this example, N_ELEMENTS is used to determine the number of elements in a two-dimensional array.

; Create a 3-by-2 integer array.

a = INDGEN(3, 2)

PRINT, a

; PV-WAVE prints:

; 0       1       2

; 3       4       5

; Display the number of elements in a.

PRINT, N_ELEMENTS(a)

; PV-WAVE prints: 6

; Delete the variable a.

DELVAR, a

INFO, a

; PV-WAVE prints: VARIABLE    UNDEFINED = <Undefined>

PRINT, N_ELEMENTS(a)

; PV-WAVE prints: 0