php - 将整数插入数组的问题

Question

我一直在尝试解决 Project Euler 问题 1，但我觉得我缺少一些基本的东西。你能帮我修复我的错误吗？

我首先尝试了这个:

<?php
/* 
** Project Euler Problem 1
** If we list all the natural numbers below 10 that are multiples of 3 or 5,
** we get 3, 5, 6 and 9. The sum of these multiples is 23. 
** Find the sum of all the multiples of 3 or 5 below 1000.
*/
$numberOne = 3;
$numberTwo = 5;
$endingIndex = 1000;
$multiplesOfNumbers = array();  

for ($index = 1; $index <= $endingIndex; $index++) {
    if ($index % $numberOne == 0 && $index % $numberTwo == 0) {
        $multipleOfNumbers[] = $index;
    }
}
echo $multiplesOfNumbers;
?>

输出:

Array

所以我尝试用 array_push 代替，像这样:

<?php
/* 
** Project Euler Problem 1
** If we list all the natural numbers below 10 that are multiples of 3 or 5,
** we get 3, 5, 6 and 9. The sum of these multiples is 23. 
** Find the sum of all the multiples of 3 or 5 below 1000.
*/
$numberOne = 3;
$numberTwo = 5;
$endingIndex = 1000;
$multiplesOfNumbers = array();  

for ($index = 1; $index <= $endingIndex; $index++) {
    if ($index % $numberOne == 0 && $index % $numberTwo == 0) {
        // $multipleOfNumbers[] = $index;
        array_push($multiplesOfNumbers, $index);
    }
}
echo $multiplesOfNumbers;
?>

输出是一样的。我错过了什么？

Answer 1

试试这个方法:

print_r($multiplesOfNumbers);