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Switch
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Switch

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Switch[expr,form1,value1,form2,value2,…]

evaluates expr, then compares it with each of the formi in turn, evaluating and returning the valuei corresponding to the first match found.

Details

  • Only the valuei corresponding to the first formi that matches expr is evaluated. Each formi is evaluated only when the match is tried.
  • If the last formi is the pattern _, then the corresponding valuei is always returned if this case is reached.
  • If none of the formi match expr, the Switch is returned unevaluated.
  • Switch has attribute HoldRest.
  • You can use Break, Return, and Throw in Switch.

Examples

Basic Examples  (2)Summary of the most common use cases

Process Boolean value to 1 or 0, giving a message and defaulting to 0 when not Boolean:

In[1]:=1
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https://wolfram.com/xid/0mq47q-z2yvn
In[2]:=2
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https://wolfram.com/xid/0mq47q-lo4xr2
In[3]:=3
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https://wolfram.com/xid/0mq47q-b4268r
Out[3]=3

Give a suggested symbolic transformation for an expression:

In[1]:=1
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https://wolfram.com/xid/0mq47q-l5vqgl
In[2]:=2
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https://wolfram.com/xid/0mq47q-fw7egc
Out[2]=2

Try the transformation:

In[3]:=3
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https://wolfram.com/xid/0mq47q-yxnd2
Out[3]=3
Wolfram Research (1988), Switch, Wolfram Language function, https://reference.wolfram.com/language/ref/Switch.html.
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Wolfram Research (1988), Switch, Wolfram Language function, https://reference.wolfram.com/language/ref/Switch.html.

Text

Wolfram Research (1988), Switch, Wolfram Language function, https://reference.wolfram.com/language/ref/Switch.html.

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Wolfram Research (1988), Switch, Wolfram Language function, https://reference.wolfram.com/language/ref/Switch.html.

CMS

Wolfram Language. 1988. "Switch." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Switch.html.

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Wolfram Language. 1988. "Switch." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Switch.html.

APA

Wolfram Language. (1988). Switch. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Switch.html

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Wolfram Language. (1988). Switch. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Switch.html

BibTeX

@misc{reference.wolfram_2025_switch, author="Wolfram Research", title="{Switch}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/Switch.html}", note=[Accessed: 26-March-2025 ]}

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@misc{reference.wolfram_2025_switch, author="Wolfram Research", title="{Switch}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/Switch.html}", note=[Accessed: 26-March-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_switch, organization={Wolfram Research}, title={Switch}, year={1988}, url={https://reference.wolfram.com/language/ref/Switch.html}, note=[Accessed: 26-March-2025 ]}

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@online{reference.wolfram_2025_switch, organization={Wolfram Research}, title={Switch}, year={1988}, url={https://reference.wolfram.com/language/ref/Switch.html}, note=[Accessed: 26-March-2025 ]}