How to use php to find odd numbers within 100

Implementation steps: 1. Use the for statement control range to traverse the numbers from 1 to 100, the syntax is "for ($i = 1; $i

The operating environment of this tutorial: windows7 system, PHP8.1 version, DELL G3 computer

In php, we can use the for loop to Find an odd number within 100.

Implementation idea:

• First use a for loop to control the range and traverse the numbers from 1 to 100

• Then in the loop, use the if statement to determine whether number i is an odd number
  

  • If it is an odd number, output the current number i That’s it

So how do you determine whether a number is odd or even? In fact, the essence is to determine whether the number is divisible by 2:

• If it can be divisible by 2, it is an even number

• If not If it is divisible by 2, it is an odd number

So how to implement the integer division function in PHP?

In PHP, you can use the remainder operator "%" to determine whether it is divisible.

• If a number is divided by 2 and there is no remainder (0), then it is divisible by 2, which is an even number

• If If a number is divided by 2 and there is a remainder (not 0), then it is not divisible by 2, that is, it is an odd number.

Okay, after analyzing this, everyone should understand how to judge whether Is it an odd number or an even number? is to use the "%" operator. Grammar:

$num%2==0

Let’s use an example to learn more about PHP’s method of finding odd numbers within 100:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
for ($i = 1; $i <= 100; $i++) {
    if($i % 2 != 0){
    	echo $i." ";
    }
}
?>

There is a lot of data. It can be stored in an array and improved:

<?php
header(&#39;content-type:text/html;charset=utf-8&#39;);   
for ($i = 1; $i <= 100; $i++) {
    if($i % 2 != 0){
    	$arr[]=$i;
    }
}
var_dump($arr);
?>

After knowing all the odd numbers within 100, you can also use array_sum() to find the sum of the odd numbers:

$sum=array_sum($arr);
echo "100以内的奇数和：".$sum;

Description: The array_sum() function can return the sum of all values ​​in the array.

Recommended learning: "PHP Video Tutorial"

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