問題描述

我正在嘗試在 Java 中格式化兩個數組以打印如下內容:

I'm trying to format two arrays in Java to print something like this:

Inventory Number      Books                          Prices
------------------------------------------------------------------
1                     Intro to Java                  $45.99
2                     Intro to C++                   $89.34
3                     Design Patterns                $100.00
4                     Perl                           $25.00

我正在使用以下代碼:

for(int i = 0; i < 4; i++) {
        System.out.print(i+1);
        System.out.print("                     " + books[i] + " ");
        System.out.print("                 " + "$" + booksPrices[i] + " ");
        System.out.print("
");
    }

但是我得到了這個格式很差的結果:

But I am getting this poorly formatted result instead:

Inventory Number      Books                          Prices
------------------------------------------------------------------
1                     Intro to Java                  $45.99 
2                     Intro to C++                  $89.34 
3                     Design Patterns                  $100.0 
4                     Perl                  $25.0 

如何將所有列直接排列在頂部標題下方?

How would I go about lining all the columns up directly under the headers at the top?

有沒有更好的方法來做到這一點?

Is there a better way to go about doing this?

推薦答案

你應該看看格式:

System.out.format("%15.2f", booksPrices[i]);   

這將提供 15 個插槽，并在需要時用空格填充它.

which would give 15 slots, and pad it with spaces if needed.

但是，我注意到您沒有右對齊您的數字，在這種情況下，您希望在書籍字段中左對齊:

However, I noticed that you're not right-justifying your numbers, in which case you want left justification on the books field:

System.out.printf("%-30s", books[i]);

這是一個工作片段示例:

Here's a working snippet example:

String books[] = {"This", "That", "The Other Longer One", "Fourth One"};
double booksPrices[] = {45.99, 89.34, 12.23, 1000.3};
System.out.printf("%-20s%-30s%s%n", "Inventory Number", "Books", "Prices");
for (int i=0;i<books.length;i++){
    System.out.format("%-20d%-30s$%.2f%n", i, books[i], booksPrices[i]);
}

導致:

Inventory Number    Books                         Prices
0                   This                          $45.99
1                   That                          $89.34
2                   The Other Longer One          $12.23
3                   Fourth One                    $1000.30

這篇關于按列打印 Java 數組的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！