isequal - Test arrays for equality

Syntax

Description

tf = isequal(A, B, ...) returns logical 1 (true) if the input arrays have the same contents, and logical 0 (false) otherwise. Nonempty arrays must be of the same data type and size.

Tips

When comparing structures, the order in which the fields of the structures were created is not important. As long as the structures contain the same fields, with corresponding fields set to equal values, isequal considers the structures to be equal. See Example 2, below.

When comparing numeric values, isequal does not consider the data type used to store the values in determining whether they are equal. See Example 3, below. This is also true when comparing numeric values with certain nonnumeric values, such as logical true and 1, or the character A and its numeric equivalent, 65.

When comparing handle objects, use eq or the == operator to test whether objects are the same handle. Use isequal to test if objects have equal property values, even if those objects are different handles.

NaNs (Not a Number), by definition, are not equal. Therefore, arrays that contain NaN elements are not equal, and isequal returns zero when comparing such arrays. See Example 4, below. Use the isequaln function when you want to test for equality with NaNs treated as equal.

isequal recursively compares the contents of cell arrays and structures. If all the elements of a cell array or structure are numerically equal, isequal returns logical 1.

Examples

Example 1

Given

A =                 B =                 C =
     1     0             1     0             1     0
     0     1             0     1             0     0

isequal(A,B,C) returns 0, and isequal(A,B) returns 1.

Example 2

When comparing structures with isequal, the order in which the fields of the structures were created is not important:

A.f1 = 25;    A.f2 = 50
A = 
    f1: 25
    f2: 50

B.f2 = 50;    B.f1 = 25
B = 
    f2: 50
    f1: 25

isequal(A, B)
ans =
     1

Example 3

When comparing numeric values, the data types used to store the values are not important:

A = [25 50];   B = [int8(25) int8(50)];

isequal(A, B)
ans =
     1

Example 4

Arrays that contain NaN (Not a Number) elements cannot be equal, since NaNs, by definition, are not equal:

A = [32 8 -29 NaN 0 5.7];
B = A;

isequal(A, B)
ans =
     0

See Also

eq | is* | isa | isequaln | relational operators | strcmp

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