在 MATLAB 中清除内存中的项目

在本文中，我们将讨论“从内存中清除项目”，在 MATLAB 中可以使用清除操作来完成。

清除操作用于从内存或当前活动工作区中清除指定的项目。它用于释放系统内存。

Syntax:

clear

clear name1 … nameN

clear -regexp expr1 … exprN

clear(‘a’, ‘b’, ‘c’)

clear([‘a’ ‘b’ ‘c’])

clear functions

clear mex

clear global

clear all

clear keyword

这里，

• clear：这用于从当前工作区中删除所有项目。
• clear name1, ... nameN：这用于从内存中删除诸如 name1 ... nameN 之类的变量。
• clear -regexp expr1 ... exprN：这用于删除与列出的任何正则表达式匹配的所有变量。这仅用于删除变量。
• clear('a', 'b', 'c')和clear(['a' 'b' 'c']):这 如果指定的变量存在于当前函数的本地环境中，则用于删除其变量。
• 清除功能：这仅用于删除未锁定的功能。如果一个函数被锁定或当前正在运行，它不会从内存中清除。
• clear mex：这用于清除内存中的所有 MEX 文件。
• clear global：用于清除所有全局变量。
• clear all：这用于从内存中删除所有变量、函数和 MEX 文件。
• 清除关键字：用于清除关键字指示的项目。

示例 1：

Matlab

% MATLAB code for removes all the
% items so its output is blank.
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear operation to
% clear all the above specified items
clear
 
% Getting the remaining items
whos

此示例将清除所有值。

示例 2：

MATLAB

% MATLAB code for Clear operation
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear operation to
% clear B and D items
clear B D;
 
% Getting the remaining items
whos

输出：

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       A           1x1                          8  double
       C           1x1                          8  double
Total is 2 elements using 16 bytes

示例 3：

MATLAB

% MATLAB code for clear expression values
% Initializing some expressions
exp1 = 'ab+c';
exp2 = 'a-c';
exp3 = '+/gfg';
 
% Calling the clear operation to
% clear expression exp2
clear -regexp ^exp2;
 
% Getting the remaining expressions
whos

输出：

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       exp1        1x4                          4  char
       exp3        1x5                          5  char
Total is 9 elements using 9 bytes

示例 4：

MATLAB

% MATLAB code for clear()
% Initializing some items
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear function
% to clear items A and C
clear ('A', 'C');
 
% Again calling the clear function
% to clear D items
clear (['D']);
 
% Getting the remaining items B
whos

输出：

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       B           1x1                          8  double
Total is 1 element using 8 bytes

示例 5：

MATLAB

% MATLAB code for clear global variable data
% Initializing some items
global A;
A = 2;
B = 4;
C = 6;
D = 8;
 
% Calling the clear function
% to clear global items only
clear global
 
% Getting the remaining items
whos

输出：

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
       B           1x1                          8  double
       C           1x1                          8  double
       D           1x1                          8  double
Total is 3 elements using 24 bytes

示例 6：

MATLAB

% MATLAB code for clear value of variable
% Initializing some items
global A;
A = 2;
B = 4;
keyword = 6;
D = 8;
 
% Calling the clear function
% to clear keyword items only
clear keyword
 
% Getting the remaining items
whos

输出：

Variables in the current scope:
  Attr Name        Size                     Bytes  Class
  ==== ====        ====                     =====  =====
    g  A           1x1                          8  double
       B           1x1                          8  double
       D           1x1                          8  double
Total is 3 elements using 24 bytes

示例 7：

MATLAB

% MATLAB code for all types of items are
% cleared so nothing is printed as output.
% Initializing some items
global A;
A = 2;
B = 4;
keyword = 6;
D = 8;
 
% Calling the clear function
% to clear all items
clear all
 
% Getting the remaining items
whos

此示例将清除所有值。