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DADiSP Worksheet Functions > Function Categories > Data Manipulation and Editing > += -= /= *= >>= <<= &= |= %= (Assignment Operators)
Operate and assign the value of an expression.
val1 op= val2
|
val1 |
- |
A scalar, series, or table. |
|
val2 |
- |
A scalar, series, or table. |
A scalar, series, or table.
j = 10;
j += 2;
Variable j contains the value 12.
W1: {1, 2, 3, 4}
W1 += 2
W1 contains the series {3, 4, 5, 6}. Each value of the series is incremented by the value 2.0.
a = {1, 2, 3, 4}
a &= 0x01
Variable a contains the series {1, 0, 1, 0} indicating the values that have the lowest bit set.
b = {1, 2, 3, 4}
b |= 0x01
Variable b contains the series {1, 3, 3, 5}.
b = {1, 2, 3, 4}
b |^= 0x01
Variable b contains the series {0, 3, 2, 5}.
The following assignment operators are supported:
|
Operator |
Description |
|
+= |
add then assign |
|
-= |
subtract then assign |
|
*= |
multiply then assign |
|
/= |
divide then assign |
|
%= |
modulo then assign |
|
>>= |
bit right shift then assign |
|
<<= |
bit left shift then assign |
|
&= |
bit and shift then assign |
|
|= |
bit or then assign |
|
|^= |
bit xor then assign |
|
@= |
append then assign |
|
@@ |
concatenate |
If e1 and e2 are expressions, then
e1 op= e2
is equivalent to
e1 = (e1) op (e2)
except that e1 is computed only once. Notice the parenthesis.
x *= y + 1
is equivalent to
x = x * (y + 1)
not
x = x * y + 1
Assignment operators are not only fast and concise, they correspond better to the way people think. We say "add 2 to j" or "increment j by 2," not "take j, add 2, then put the result back into j." Thus, j += 2.
The statement:
a = b @@ c
is more compact and equivalent to
a = concat(b, c)
The statement:
a @= b
is equivalent to
append(a, b)
The @= operator appends the series B to the end of series A in place. a @= b is much faster than a = a @@ b for large series because @= operates on the existing series whereas @@ creates and assigns a new series.
See DADiSP/VectorXL to optimize arithmetic operations on series.