Julia Quick Note [01] How to use variables and constants

How to use variables and constants (example of how to write)

`note01`


◆ Variable declaration

integer
　　x = 1
　　y = -100

Real number
　　a = 2.0
　　b = 3.14
　　c = -5.0

◆ Declaration of constants
　const t = 2020

◆ Character expression
　x = 2
　y = 2x + 1
　h = sin(pi / 2)

Commentary

In Julia, like JavaScript and Python, it is not necessary to specify the type of the variable (actually, it has the type internally). You can set the value intuitively.

(1) Addition, subtraction, multiplication of integers

The calculation result is also an integer.

(2) Division between integers

The calculation result is a real number for both divisible and indivisible numbers.

(3) Calculation of mixed integers and real numbers

The calculation result is a real number.

(4) Handling of constants

Constants are declared as const. If you change it later, an error will occur.

(5) About character expressions

You can treat variables like mathematical expressions. You can also use mathematical arithmetic functions. The "$ \ pi $" and "e" used above are the following mathematical constants, respectively.

letter	Meaning and usage
\pi	Pi. On the keyboard\Enter "pi" and press the tab key.
e	Napier number(Natural logarithm).. On the keyboard\Enter "euler" and press the tab key.

$ \ Pi $ can also be calculated by writing pi.

There are many other mathematical formulas. Please refer to the official document below for details.

:paperclip: Julia - Mathematics https://docs.julialang.org/en/v1/base/math/

(6) About reserved variable names

In Julia, there are the following reserved words. You cannot use these as variable names on your own.

baremodule, begin, break, catch, const, continue, do, else, elseif, end, export, false, finally, for, function, global, if, import, let, local, macro, module, quote, return, struct, true, try, using, while

Please refer to the official document below for details.

:paperclip: Julia - Keywords https://docs.julialang.org/en/v1/base/base/#Keywords

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Julia Quick Look Note [01] How to use variables and constants

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Related information

: paperclip: Julia --Official page https://julialang.org/

: paperclip: Julia --Japanese official document https://julia-doc-ja.readthedocs.io/ja/latest/index.html

: paperclip: First time Julia and installation (Windows & Linux) https://qiita.com/ttlabo/items/b05bb43d06239f968035

:paperclip: Julia - Mathematics https://docs.julialang.org/en/v1/base/math/

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