How to output all leap years in the 20th century in PHP

In the previous article "How to obtain a 10-line Yang Hui triangle through a PHP program", we introduced the method of using PHP to output any line of Yang Hui triangle. Interested friends can learn about it~

In this article, we will learn how to use PHP to determine whether a given year is a leap year, and how to output all leap years in the 20th century.

First of all, let’s briefly understandWhat is a leap year? A leap year refers to a year with a leap day in the Gregorian calendar (that is, February has 29 days).

There are certain rules for leap years. According to this rule, you can determine whether a given year is a leap year

• Ordinary leap years: Gregorian calendar years can A leap year is one that is divisible by 4 and not divisible by 100. (For example, 2004 is a leap year, and 1900 is not a leap year)

  That is:

$year%4==0&&$year%100!=0

• Century leap year: Gregorian calendar year A leap year is one that is divisible by 400 but not divisible by 3200. (For example, the year 2000 is a leap year, and the year 3200 is not a leap year)

  That is:
  

$year%400==0&&$year%3200!=0

Let’s summarize it and see how to output the 20th century All leap years

Analysis:

Because all leap years in the 20th century are output, a for loop must be used to limit the range; and the 20th century refers to 1901 The period from January 1st to December 31st, 2000, so the for loop can be written like this:

for($year = 1901; $year <= 2000; $year++){
  //循环体
}

Then in the loop body, use the if else statement to connect the algorithms for leap year judgment together:

if($year%400==0&&$year%3200!=0){	

}
else if($year%4==0&&$year%100!=0){

}

So we can give a method to determine leap years and output all leap years in the 20th century:

";//世纪年里的闰年
	}
	else if($year%4==0&&$year%100!=0){
		echo $year."是普通闰年!
";//普通年里的闰年 
	}
}
?>

The output result is:

Okay, that’s all. If you want to know anything else, you can click this. → →php video tutorial

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