PHP、Printf、Sprintf 函数 [英] PHP, Printf,Sprintf Functions

问题描述

我正在研究printf，sprintf，但我没有理解几点，如果有人可以帮助我理解这些点，

I am studying about printf,sprintf and i didnt understand few points, if can some one please help me understand thos points,

此链接位于 PHP 手册:

有从一到六的解释:

我不明白的是:第一个和第二个(1(符号说明符)，2(填充说明符))，如果有人可以帮我举个例子，我会非常感激.

What i didnt understand is: The First and The Second(1(sign specifier), 2(padding specifier)), if can some one please help me with example for thos i will be very thankful.

推荐答案

符号说明符强制一个符号，即使它是正的.所以，如果你有

The sign specifier forces a sign, even if it's positive. So, if you have

$x = 10;
$y = -10;
printf("%+d", $x);
printf("%+d", $y);

你会得到:

+10
-10

填充说明符添加左填充，以便输出始终采用一定数量的空格，这使您可以对齐一堆数字，这在生成带有总计等的报告时很有用.

The padding specifier adds left padding so that the output always takes a set number of spaces, which allows you to align a stack of numbers, useful when generating reports with totals, etc.

 $x = 1;
 $y = 10;
 $z = 100;
 printf("%3d\n", $x);
 printf("%3d\n", $y);
 printf("%3d\n", $z);

你会得到:

   1
  10
 100

如果在填充说明符前面加上零，字符串将被零填充而不是空格:

If you prefix the padding specifier with a zero, the strings will be zero padded instead of space padded:

 $x = 1;
 $y = 10;
 $z = 100;
 printf("%03d\n", $x);
 printf("%03d\n", $y);
 printf("%03d\n", $z);

给出:

 001
 010
 100

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