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- Arithmetic operators
- +,-,*,/ Classical arithmetic operators. Addition of a value to ARRAYs, SETs,
LISTs, STRINGs and DATEs.
- Usage
- a + b, a - b, a * b, a / b, - a : arithmetic operators.
set + val, set - val : physical addition of an element to a set object.
stg1 + stg2 : contatenation of a character to a STRING.
d1 + i, d1 - i : addition of i time units to a date.
- Arguments
- a,b (INT or REAL) : numerical values. For arithmetic operators, any combination of types INT and REAL is possible.
set (ARRAY(T)) or set (SET(T)) or set (LIST(...)), val (T)
stg1 (STRING), stg2 (STRING)
d1 (DATE), i (INT).
- Returned Object
- - For arithmetic operators, the result is INT only in the case where both a and b are INTs. Otherwise the result is REAL. If either a or b is Undef, returns Undef. A division by 0 returns an Undef value.
- When an element is added to or removed from a set object set, the initial object is physically affected by the operation. The value returned by either these operators is the (modified) argument itself (and not a modification of a copy of the argument). If set is Undef, returns Undef. If set is not Undef and val is Undef, then the result
- For a STRING, on the contrary, the concatenation of the two strings is a new STRING, different from both stg1 and stg2.
- For date incrementation, cf. Date operators.
- Description
- - If a and b are integer values, a / b performs an integral division. The arguments have to be casted to REALs if one wants to apply a division between arguments considered as REAL numbers.
- '+' and '-' can be used to physically add or remove elements from a set object.
- If set is an ARRAY, set + val makes the element val be appended at the end of set. set - val removes the first occurence of element val in the array set1.
- '+' and '-' can be used to concatenate two strings.
- '+' and '-' can be used for adding i time units to a date, cf. Date operators.
- Side Effect
- Important: contrary to most functions in AML which leave their argument unchanged, this fonction modifies its set argument. The value returned is the modified argument.
- See Also
-
Union,
Inter,
SetMinus,
Date operators,
ToSet,
ToArray.
Examples
AML># Arithmetic operators
AML> 9 / 2
<INT>4
AML> 5 + 3
<INT>8
AML> 5.0 + 3
<REAL>8
AML> 9 / 0
Undef
AML> # Addition / Deletion of elements of set objects
AML> a=[1,2,4,3,4,5,6,4]
<ARRAY(INT)> [1,2,4,3,4,5,6,4]
AML> a + 2
<ARRAY(INT)> [1,2,4,3,4,5,6,4,2]
AML> a
<ARRAY(INT)> [1,2,4,3,4,5,6,4,2]
AML> a - 4
<ARRAY(INT)> [1,2,3,4,5,6,4,2]
AML> a - 4
<ARRAY(INT)> [1,2,3,5,6,4,2]
AML> s=Set(1,2,4,3,4,5,6,4)
<SET(INT)> [1,2,3,4,5,6]
AML> s + 2
<SET(INT)> [1,2,3,4,5,6]
AML> s + 7
<SET(INT)> [1,2,3,4,5,6,7]
AML> s
<SET(INT)> [1,2,3,4,5,6,7]
AML> s - 2
<SET(INT)> [1,3,4,5,6,7]
AML> # Concatenation of strings
AML> stg1 = "AMAP" ; stg2 = "mod"
<STRING> mod
AML> stg1 + stg2
<STRING> AMAPmod
AML> stg1
<STRING> AMAP
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