Java 多维数组中array.length 和array[0].length 之间的区别？
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Difference between array.length and array[0].length in a multi-dimensional array?
提问by Isaac Adni
When I create a new multi-dimensional array (in this case an array of objects)
当我创建一个新的多维数组（在这种情况下是一个对象数组）
public Block[][] block = new Block[50][70];
What is the difference between:
有什么区别：
block.length
and
和
block[0].length
and then what is
然后是什么
block[1].length
采纳答案by gexicide
What do you expect? You have a multidimensional array. Thus, there is more than one dimension. Each dimension has a length. With block.lengthyou get the length of the first one (i.e. 50), with block[x].length, you get the length of the second one (i.e., 70).
你能指望什么？你有一个多维数组。因此，存在不止一个维度。每个维度都有一个长度。随着block.length你得到的第一个（即长度50），有block[x].length，你得到的第二个（即长度70）。
Since you allocated your array like this, all block[x].lengthwill be equal, no matter what you choose for x. However, you could have an array where the nested arrays have different lengths, then block[0].lengthmight not be equal to block[1].length.
既然你这样分配了你的数组block[x].length，那么无论你选择什么，一切都将是平等的x。但是，您可能有一个数组，其中嵌套数组的长度不同，然后block[0].length可能不等于block[1].length。
回答by Shahar
block.lengthis the number of rows. block[0].lengthis the number of columns in row 0. block[1].lengthshould have the same value as block[0].lengthsince it has the same number of columns as the first row.
block.length是行数。block[0].length是第 0 行中的列数。block[1].length应该具有相同的值，block[0].length因为它与第一行的列数相同。
回答by Bohemian
If you think of Block[][]as being rows and columns of Block, and each row being a Block[]of columns, and an array of rows would be a Block[][], then:
如果您认为Block[][]是 的行和列Block，每行是列的 a ，而行Block[]的数组是 a Block[][]，那么：
block.length // the number of rows
block[0].length // the number of columns on row 0
block[1].length // the number of columns on row 1
// etc
回答by micronyks
here you have two dimensional array. it has 50 rows and 70 columns. it means...
在这里你有二维数组。它有 50 行和 70 列。它的意思是...
about block array... block array will look like (row & column wise)
关于块数组...块数组看起来像（行和列）
block= 0...1...2...3...4...SO..ON...69
1
2 50
3
4
5
SO..ON
..
..
49
Now you are having tabular format of block array. now lets say I want to get value of block[2][3]... it means 2th row and 3rd column which is 50 as shown above.
现在您拥有块数组的表格格式。现在可以说我想获得 block[2][3] 的值......这意味着第 2 行和第 3 列是 50，如上所示。
block.length total rows of Block array.
block.length 块数组的总行数。
block[0] is referring to 0th row of Block array and so block[0].length gives you columns associated with 0th row which 70 so ans would be 70 (Note:total count)....
block[0] 指的是 Block 数组的第 0 行，因此 block[0].length 为您提供与第 0 行相关联的列，其中 70 为 70（注意：总计数）...
and so on....
等等....
