ifNull

ifNull(X, Y)

X is a scalar/pair/vector/matrix.

Y is a scalar/pair/vector/matrix.

X and Y must have the same data type.

Determine whether X is NULL. If it is NULL, return X; if not, return Y.

x = take(1..5 join NULL 6,7)
y = 1..7
ifNull(x,y)
// output
[1,2,3,4,5,,7]

y1 = int(take(1..5 join int(),6))$2:3
x1 = int(take(100,6))$2:3
ifNull(x1,y1)

If X is a vector and Y is a matrix with n rows and m columns, the length of X is n*m.

m=int(take(1..4 join NULL 8,6))
ifNull(m,y1)
// output
[100,100,100,100,,100]