ifn()

Here’s how to use ifn() function.

A .ifn()

Description:

Get the first non-null member of a sequence.

Syntax:

A.ifn()

Equivalent to ifn(x1,…,xn)

Note:

The function gets the first non-null member of sequence A.

Parameter:

A	A sequence with the length of n

Return value:

The first non-null member of the sequence.

Example:

	A
1	=[1,2,4].ifn()	1
2	=[null,2,3,4].ifn()	2
3	=[null,2,null,4].ifn()	2
4	=ifn(null,1,2,4)	1

Related function:

  A.ifn(x)

A. ifn( x )

Description:

Compute x with each member of the sequence and return the first non-null member of the new sequence.

Syntax:

A.ifn(x)

Equivalent to A.(x).ifn()

Note:

The function loops through members of sequence A to compute expression x and return the first non-null member of the new sequence.

Parameter:

A	A sequence
x	Generally an expression of a single field name, or a legal expression composed of multiple field names

Return value:

The first non-null member of the new sequence

Example:

	A
1	=demo.query("select * from EMPLOYEE")
2	=A1.ifn(SALARY)	Return the first non-null value of SALARY
3	=A1.(SALARY+100).ifn()	Add 100 to the salary of each employee and return the salary of the first employee

Related function:

  A.ifn()