Question

在PHP中使用嵌套for循环，我必须创建以下模式：

- - - - - - - - - - - - - - -
- - - - - - - + - - - - - - -
- - - - - - + + + - - - - - -
- - - - - + + + + + - - - - -
- - - - + + + + + + + - - - -
- - - + + + + + + + + + - - -
- - + + + + + + + + + + + - -
- + + + + + + + + + + + + + -
+ + + + + + + + + + + + + + +

我试过这样做，并编写了以下代码：

$pluscount = -1;
$mincount  = 8;
for ($rows = 0; $rows <= 8; $rows++) {
    for ($min = 0; $min < $mincount; $min++) {
        echo " - ";
    }
    for ($plus = 0; $plus < $pluscount; $plus++) {
        echo " + ";
    }
    for ($min = 0; $min < $mincount; $min++) {
        echo " - ";
    }
    $pluscount += 2;
    $mincount  = (15 - $pluscount) / 2;
    echo "<br />";
}

然而，这导致：

- - - - - - - - - - - - - - - - 
- - - - - - - + - - - - - - - 
- - - - - - + + + - - - - - - 
- - - - - + + + + + - - - - - 
- - - - + + + + + + + - - - - 
- - - + + + + + + + + + - - - 
- - + + + + + + + + + + + - - 
- + + + + + + + + + + + + + - 
+ + + + + + + + + + + + + + +

如您所见，第一行不正确。我该如何解决这个问题？

Answer 1

您可以使用str_repeat()替换子循环，并使用substr()修剪最后一部分。

var The_Function_I_Need = {
  "x^2": function(x) {
    return Math.pow(x, 2);
  },
  "x*2+5": function(x) {
    return 2 * x + 5;
  },
  "x+y": function(x, y) {
    return x + y;
  }
}

console.log(The_Function_I_Need["x^2"](4))
console.log(The_Function_I_Need["x*2+5"](4))
console.log(The_Function_I_Need["x+y"](2, 4))

Answer 2

这是解决问题的一种黑客方式。我不是整体解决方案的粉丝。

$pluscount = -1;
$mincount  = 7;
for ($rows = 0; $rows <= 8; $rows++) {
    for ($min = 0; $min < $mincount; $min++) {
        echo " - ";
    }

    for ($plus = 0; $plus < $pluscount; $plus++) {
        echo " + ";
    }

    if ($rows == 0) {
            $mincount += 1;
    }

    for ($min = 0; $min < $mincount; $min++) {
        echo " - ";
    }
    $pluscount += 2;
    $mincount  = (15 - $pluscount) / 2;
    echo "<br />";
}

我认为你最好从一个15' - '字符串开始，并根据你所在的行替换你需要的数字。

//Pseudo-code
plusCount = -1;
baseString = "---------------";
startIndex = 7;
for (row = 0; row < 10; row++) {
     if(plusCount > 0) {
         //string replace startingLocation = startIndex - plusCount; number = pluscount
     } else {
         //baseString
     }
}

Answer 3

$pluscount = -1;
$mincount  = 8;
for ($rows = 0; $rows <= 8; $rows++) {
    for ($min = 0; $min < $mincount; $min++) {
        echo " - ";
    }
    for ($plus = 0; $plus < $pluscount; $plus++) {
        echo " + ";
    }
    for ($min = 0; $min < min($mincount, 7); $min++) {
        echo " - ";
    }
    $pluscount += 2;
    $mincount  = (15 - $pluscount) / 2;
    echo "<br />";
}

Answer 4

我知道最好的答案已经被选中，但它让我回到原点，当时一切都变得简单了，我开始学习编程......无法抵挡走过记忆的道路;）

$xLength = 15;
$yLength = 9;
$fillerChar = '-';
$outputChar = '+';

$drawPoint = floor($xLength/2);
$endPoint  = $drawPoint;

for ($yPosition=0; $yPosition<$yLength; $yPosition++) {

    for ($xPosition=0; $xPosition<$xLength; $xPosition++) {

        if (($drawPoint < $xPosition) && ($xPosition < $endPoint)) {

            print $outputChar;

        } else {

            print $fillerChar;

        }
    }

    $drawPoint--;
    $endPoint++;

    print("\n");

}

Answer 5

<?php
    create_pyramid("+", 10);

    function create_pyramid($string, $level) {
        echo "<pre>";
        $level = $level * 2;
        print str_repeat("-",$level - 1)."<br/>";
        for($i = 1; $i <= $level; $i ++) {
            if (!($i % 2) && $i != 1)
                continue;
            print str_pad(str_repeat($string, $i),($level - 1) * strlen($string), "-" , STR_PAD_BOTH);
            print PHP_EOL;
        }
    }
?>

PHP嵌套for循环 - 金字塔形状

5 个答案: