# Integers in Arrays Give Strange Result

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For example, try this,

vec = [pi, -2, uint8(1)]

vec =

1×3 uint8 row vector

3 0 1

vec = [pi, uint16(2), int8(-2)]

vec =

1×3 uint16 row vector

3 2 0

vec = [pi, uint16(2), int16(-2)]

vec =

1×3 uint16 row vector

3 2 0

So, if one element is an integer MATLAB seem to cast every other element in the array to that integer class. If there are several integer elements all elements seem to be cast to the higher integer class and, in a draw, to the unsigned class.

This is an extremely odd behavior. One would expect all elements to be cast to a numeric class that can accurately represent all elements or, at least, all elements cast to 'double' if there are mixed numerical classes in the array.

This can lead to totally wrong results if a user supplies integers to a function, for example this one,

function y = myFun(x, k)

par = [k, -2];

y = par(1) + par(2)*cos(x);

end

myFun(0, 1) will give -1 and myFun(0, uint8(1)) will give the incorrect result 1.

So, is there some logic behind this behavior or is it a bug?

##### 0 Comments

### Accepted Answer

Steven Lord
on 15 Nov 2022

For concatenation see this documentation page. If you concatenate one or more integer arrays with one or more double arrays, the leftmost of the integer arrays will determine the type of the result.

This is the documented behavior and has been for many years. It is not a bug.

##### 7 Comments

Paul
on 15 Nov 2022

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