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Programming-Idioms

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  • Ruby

Idiom #65 Format decimal number

From the real value x in [0,1], create its percentage string representation s with one digit after decimal point. E.g. 0.15625 -> "15.6%"

s = "%.1f%%" % (100 * x)

Note that you need to use %% (double %) inside a format string to produce a literal percent sign
#include <stdio.h>
char s[7];
sprintf(s, "%.2lf%%", x * 100);

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