Java String.format(): Difference between revisions

From NovaOrdis Knowledge Base
Jump to navigation Jump to search
 
Line 59: Line 59:
String.format("%1$02x", i);
String.format("%1$02x", i);
</syntaxhighlight>
</syntaxhighlight>
will display "0a".
The result will be 0-padded (<code>flag</code> is "0"), will be displayed on two characters and more (<code>width</code> is 2) and it will be rendered as a hexadecimal (<code>conversion</code> is "x").
The result will be 0-padded (<code>flag</code> is "0"), will be displayed on two characters and more (<code>width</code> is 2) and it will be rendered as a hexadecimal (<code>conversion</code> is "x").

Latest revision as of 17:58, 26 August 2021

External

Internal

Overview

Format string:

%[argument_index$][flags][width][.precision]conversion

String

String arg = "blah"
String.format("%1$-50s", arg);

This formats the first argument (%1$) as a string "s", to occupy at least 50 characters (width) and it left-justifies it ("-").

For general argument types, the precision is the maximum number of characters to be written to the output.

Parameterized Width

int width=10;
String format = "%1$-" + width + "s";
String.format(format, s);

Floating Point

For the floating-point conversions 'e', 'E', and 'f' the precision is the number of digits after the decimal separator. The conversion is done with rounding:

double arg = 77.999
String.format("%1$.2f", arg);

will display "78.00"

Integer

int arg = 77.
String.format("%1$3d", arg);

will display " 77"

Hexadecimal Integer

Display a argument as a 0-padded hexadecimal integer on at least 2 characters. Format string:

int i = 10;
String.format("%1$02x", i);

will display "0a".

The result will be 0-padded (flag is "0"), will be displayed on two characters and more (width is 2) and it will be rendered as a hexadecimal (conversion is "x").