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# ifn()

Read（1675） Label: sequence, first non-null member,

Description:

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

Syntax:

 A.ifn(x) ifn(x1,…,xn) Equivalent to A.ifn(), where x1,…,xn are members of sequence A

Note:

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

Parameter:

 A A sequence x An expression; cannot be omitted when sequence A is a table sequence or a record sequence

Return value:

The first non-null member

Example:

When A is a sequence:

 A 1 =[1,2,4].ifn() 1. 2 =[1,2,4].ifn(~*10) 10; return the first member after computing the expression. 3 =[null,2,3,4].ifn() 2; return the first non-null member. 4 =[null,"",2,3,4].ifn() “”. 5 =ifn(null,2,3,4) 2, which is same as A3.

When A is a table sequence or a record sequence:

 A 1 =create(ID,NAME,GENDER).record([1,"Rebecca",,2,"Ashley","F",3,"Matthew","M"]) 2 =A1.ifn(NAME) Get the first non-null NAME value. 3 =A1.ifn(GENDER) Get the first non-null GENDER value.