program which has day of the year and month day

Hi All,

I'm a beginner in C.
When I read a code about "program which has day of the year and month day" in reference. I'm confuse in the code(in red color). this is an argument? or condition?

Code:

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void month_day(int year, int yearday)
{
int i, leap;


leap = year % 4 == 0 && year % 100 != 0 || year % 400 == 0;


for (i = 1; yearday > daytab[leap][i]; i++)
yearday -= daytab[leap][i];


printf("Month: %d, Day: %d\n", i, yearday);


}

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It's a boolean expression.

Here's the same thing expanded.

Code:

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if ( year % 4 == 0 && year % 100 != 0 || year % 400 == 0 ) {
  leap = 1;
} else {
  leap = 0;
}

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A boolean expression evaluates to false(0) or true(1)