., _concat

Concatenate objects

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object1. object2
_concat(object1, object2, …)


object_1.object_2 concatenates two objects.

_concat( object1, object2, ...) concatenates an arbitrary number of objects.

_concat( object1, object2) is equivalent to object1. object2. The function call _concat( object1, object2, object3, ...) is equivalent to (( object1. object2). object3). ... . _concat() returns the void object of type DOM_NULL.

The following combinations are possible:

object1object2object1. object2

E.g., x.1 creates the identifier x1.

Note that the objects to be concatenated are evaluated before concatenation. Thus, if x := y, i := 1, the concatenation x.i produces the identifier y1. However, the resulting identifier y1 is not fully evaluated. Cf. Example 2.


Example 1

We demonstrate all possible combinations of types that can be concatenated. Strings are produced if the first object is a string:

"x"."1", "x".y, "x".1, "x".f(a)

Identifiers are produced if the first object is an identifier:

x."1", x.y , x.1, x.f(a)

The concatenation operator . also serves for concatenating lists:

[1, 2] . [3, 4]

L := []: for i from 1 to 10 do L := L . [x.i] end_for: L

delete L:

Example 2

We demonstrate the evaluation strategy of concatenation. Before concatenation, the objects are evaluated:

x := "Val": i := ue: x.i

ue := 1:  x.i

An identifier produced via concatenation is not fully evaluated:

delete x: x1 := 17: x.1, eval(x.1)

The . operator can be used to create variables dynamically. They can be assigned values immediately:

delete x: for i from 1 to 5 do x.i := i^2 end_for:

Again, the result of the concatenation is not fully evaluated:

x.i $ i= 1..5


delete i, ue: (delete x.i) $ i = 1..5:

Example 3

The function _concat can be used to concatenate an arbitrary number of objects:

_concat("an", " ", "ex", "am", "ple")

_concat("0", " ".i $ i = 1..15)

_concat([], [x.i] $ i = 1..10)



A character string, an identifier, or a list

object2, …

A character string, an identifier, an integer, a list, or an expression

Return Values

Object of the same type as object1.

Overloaded By

object_1, object_2

See Also

MuPAD Functions