How to | Use Shorthand Notations
Shorthand notations are a part of
Mathematica's rich syntax system that allows multiple ways to feed arguments to functions. In addition to creating compact code, using shorthand notation lets you customize your workflow in
Mathematica.
Mathematica provides several convenient methods for entering functions.
For example, use
Length with square brackets around a list to get the length of the list:
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Using the
symbol between the function and the list does the same thing. With
you do not have to move to the end of the expression to match the square bracket:
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You can also use the
postfix notation:
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These notations extend to any function and any kind of argument:
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You can also use infix notation for functions that take two arguments:
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Pure functions are used very often in
Mathematica. They let you use a function without having to define an explicit name for it. You can use the shorthand notation for
Function to give a pure function.
Use
Function to give a pure function that raises the input to a cubic power:
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The
and
symbols can be combined to accomplish the same thing. The
symbol serves as the placeholder for the variable, while the
symbol precedes the value you wish to substitute into the function:
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Map and
Apply are essential to functional programming. Using the shorthand notations for these functions is very convenient.
Use
Map to map a function over the elements of a list:
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Using
does the same thing:
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Apply has a shorthand notation as well (
):
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Shorthand notations in
Mathematica can also be combined to produce efficient code.
Use
Map and
Function to raise each element of a list to a power and add a symbol to the result:
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Perform the same operation using the shorthand notation for
Function:
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Extend this to include the shorthand notation for
Map:
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You will often need to use previous output in a new computation. This can be done by using the
symbol, the shorthand notation for
Out.
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Use the shorthand notation for
Out, the
symbol, to specify the most recent output:
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Use
with the shorthand notation for
Part,
, to take the first element of the list:
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You can use
...
to refer to previous outputs. Get the output generated two computations ago:
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If you want to get the output from a computation that is not recent, using many
symbols can be cumbersome.
Instead, use the specific output cell number with
Out. If you evaluate this cell, you will get
Out
from your current
Mathematica session and not necessarily what is shown here:
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Here is another shorthand notation:
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While convenient, referring to previous output by label or shorthand notation can quickly get out of hand since the current evaluation is always bound to the earlier output. Therefore, you must ensure that the output you want to use is available to your current computation. It is advised that you use this notation with caution.
Working with strings can be simplified by using shorthand notations for string manipulation functions.
Joining strings together is a frequently used string operation. Do this with
StringJoin:
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Using the shorthand notation for
StringJoin,
, this same operation can be written as:
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StringExpression is a very important function that is used to represent strings. It is used by a number of string manipulation functions such as
StringReplace,
StringCases,
StringSplit, and
StringMatchQ.
Use
StringExpression to create a string expression object:
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Or directly use
, the shorthand notation for
StringExpression:
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