使用花括号和圆括号访问单元格元素的区别 [英] Difference between accessing cell elements using curly braces and parentheses

问题描述

使用圆括号 () 和花括号 {} 访问元胞数组中的元素有什么区别?

What is the difference between accessing elements in a cell array using parentheses () and curly braces {}?

例如，我尝试使用 cell{4} = [] 和 cell(4) = [].在第一种情况下，它将第 4 个^th 元素设置为 []，但在第二种情况下，它清除了单元格元素，即将单元格元素计数减少了 1.

For example, I tried to use cell{4} = [] and cell(4) = []. In the first case it sets the 4^th element to [], but in the second case it wiped out the cell element, that is, reduced the cell element count by 1.

推荐答案

把元胞数组想象成一个普通的同构数组，它的元素都是 cells.括号 (()) 只是访问 cell 包装对象，而使用大括号 ({}) 访问元素给出包含在单元格.

Think of cell array as a regular homogenic array, whose elements are all cells. Parentheses (()) simply access the cell wrapper object, while accessing elements using curly bracers ({}) gives the actual object contained within the cell.

例如

A={ [5,6], 0 , 0 ,0 };

看起来像这样:

使元素等于 [] 带括号的语法实际上是删除该元素的请求，因此当您要求执行 foo(i) = [] 删除 i-th 单元格.它不是一个赋值操作，而是一个 RemoveElement 操作，它使用类似于赋值的语法.

The syntax of making an element equal to [] with parentheses is actually a request to delete that element, so when you ask to do foo(i) = [] you remove the i-th cell. It is not an assignment operation, but rather a RemoveElement operation, which uses similar syntax to assignment.

但是，当您执行 foo{i} = [] 时，您正在为第 i 个单元格分配一个新值(这是一个空数组)，从而清除该单元格的内容.

However, when you do foo{i} = [] you are assigning to the i-th cell a new value (which is an empty array), thus clearing the contents of that cell.

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