Java syntax: Difference between revisions

Revision as of 05:58, 22 January 2021

Revision as of 01:25, 1 February 2021

Line 101:

|-

![[Binary numeral system|binary]] (introduced in Java SE 7)

|<tt>{{mono|0b11110101</tt>}} (<tt>{{mono|0b</tt>}} followed by a binary number)

|-

![[octal]]

|<tt>{{mono|0365</tt>}} (<tt>{{mono|0</tt>}} followed by an octal number)

|-

![[hexadecimal]]

|<tt>{{mono|0xF5</tt>}} (<tt>{{mono|0x</tt>}} followed by a hexadecimal number)

|-

![[decimal]]

|<tt>{{mono|245</tt>}} (decimal number)

|-

!colspan="2"|[[Floating-point]] values

|-

!rowspan="2" | float

|<tt>{{mono|23.5F</tt>}}, <tt>{{mono|.5f</tt>}}, <tt>{{mono|1.72E3F</tt>}} (decimal fraction with an optional exponent indicator, followed by <tt>{{mono|F</tt>}})

|-

|<tt>{{mono|0x.5FP0F</tt>}}, <tt>{{mono|0x.5P-6f</tt>}} (<tt>{{mono|0x</tt>}} followed by a hexadecimal fraction with a mandatory exponent indicator and a suffix <tt>{{mono|F</tt>}})

|-

!rowspan="2" | double

|<tt>{{mono|23.5D</tt>}}, <tt>{{mono|.5</tt>}}, <tt>{{mono|1.72E3D</tt>}} (decimal fraction with an optional exponent indicator, followed by optional <tt>{{mono|D</tt>}})

|-

|<tt>{{mono|0x.5FP0</tt>}}, <tt>{{mono|0x.5P-6D</tt>}} (<tt>{{mono|0x</tt>}} followed by a hexadecimal fraction with a mandatory exponent indicator and an optional suffix <tt>{{mono|D</tt>}})

|-

!colspan="2"|Character literals

|-

!char

|<tt>{{mono|'a'</tt>}}, <tt>{{mono|'Z'</tt>}}, <tt>{{mono|'\u0231'</tt>}} (character or a character escape, enclosed in single quotes)

|-

!colspan="2"|Boolean literals

|-

!boolean

|<tt>{{mono|true</tt>}}, <tt>{{mono|false</tt>}}

|-

!colspan="2"|null literal

|-

!null reference

|<tt>{{mono|null</tt>}}

|-

!colspan="2"|String literals

|-

!String

|<tt>{{mono|"Hello, World"</tt>}} (sequence of characters and character escapes enclosed in double quotes)

|-

!colspan="2"|Characters escapes in strings

|-

![[Unicode]] character

|<tt>{{mono|\u3876</tt>}} (<tt>{{mono|\u</tt>}} followed by the hexadecimal unicode code point up to U+FFFF)

|-

![[Octal]] escape

|<tt>{{mono|\352</tt>}} (octal number not exceeding 377, preceded by backslash)

|-

![[Line feed]]

|{{mono|\n}}

|<tt>\n</tt>

|-

![[Carriage return]]

|{{mono|\r}}

|<tt>\r</tt>

|-

![[Form feed]]

|{{mono|\f}}

|<tt>\f</tt>

|-

![[Backslash]]

|{{mono|\\}}

|<tt>\\</tt>

|-

![[Single quote]]

|{{mono|\'}}

|<tt>\'</tt>

|-

![[Double quote]]

|{{mono|\"}}

|<tt>\"</tt>

|-

![[Tab character|Tab]]

|{{mono|\t}}

|<tt>\t</tt>

|-

![[Backspace]]

|{{mono|\b}}

|<tt>\b</tt>

|}

Integer literals are of <code>int</code> type by default unless <code>long</code> type is specified by appending <code>L</code> or <code>l</code> suffix to the literal, e.g. <code>367L</code>. Since Java SE 7, it is possible to include underscores between the digits of a number to increase readability; for example, a number <tt>{{mono|145608987</tt>}} can be written as <tt>{{mono|145_608_987</tt>}}.

===Variables===

Line 206:

===Code blocks===

The separators <tt>{</tt>{mono|{}} and <tt>{{mono|}}}</tt> signify a code block and a new scope. Class members and the body of a method are examples of what can live inside these braces in various contexts.

Inside of method bodies, braces may be used to create new scopes, as follows:

Line 278:

</syntaxhighlight>

Classes with the <code>public</code> modifier must be placed in the files with the same name and <tt>{{mono|java</tt>}} extension and put into nested folders corresponding to the package name. The above class <code>myapplication.mylibrary.MyClass</code> will have the following path: <code>myapplication/mylibrary/MyClass.java</code>.

===Import declaration===