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issorted - Determine whether set elements are in sorted order

Syntax

TF = issorted(A) TF = issorted(A, 'rows')

Description

TF = issorted(A) returns logical 1 (true) if the elements of A are in sorted order, and logical 0 (false) otherwise. Input A can be a vector or an N-by-1 or 1-by-N cell array of strings. A is considered to be sorted if A and the output of sort(A) are equal.

TF = issorted(A, 'rows') returns logical 1 (true) if the rows of two-dimensional matrix A are in sorted order, and logical 0 (false) otherwise. Matrix A is considered to be sorted if A and the output of sortrows(A) are equal.

Note Only the issorted(A) syntax supports A as a cell array of strings.

Remarks

For character arrays, issorted uses ASCII, rather than alphabetical, order.

You cannot use issorted on arrays of greater than two dimensions.

Examples

Example 1 — Using issorted on a vector

A = [5 12 33 39 78 90 95 107 128 131];

issorted(A)
ans = 
     1

Example 2 — Using issorted on a matrix

A = magic(5)
A =
    17    24     1     8    15
    23     5     7    14    16
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9

issorted(A, 'rows')
ans = 
     0

B = sortrows(A)
B =
     4     6    13    20    22
    10    12    19    21     3
    11    18    25     2     9
    17    24     1     8    15
    23     5     7    14    16

issorted(B)
ans = 
     1

Example 3 — Using issorted on a cell array

x = {'one'; 'two'; 'three'; 'four'; 'five'};
issorted(x)
ans =
     0

y = sort(x)
y = 
    'five'
    'four'
    'one'
    'three'
    'two'

issorted(y)