# Lab09: String Conversions solutions

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## Description

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Part 1
This is one way to convert a string into a vector of digits.
n = 123;
s = num2str(n) % convert n to a string
s =
123
V = double(s) % convert chars to character codes
V =
49 50 51
V = V – ‘0’ % convert character codes to digits 0-9
ans =
1 2 3
Type each of these statements to see how they work. Try them with different
numbers. Can you combine these statements into one statement that does the
same thing?
Part 2
Turn the conversion statement (or statements) from part 1 into a function
called num2vec.
Examples of using the function:
num2vec(123)
ans =
1 2 3
num2vec(98765)
ans =
9 8 7 6 5
2
length(ans)
ans =
5
Part 2a
Write a second num2vec function (call it num2vec2) that does the same thing
that num2vec does, but it uses a loop to create the vector. In this function you
are not allowed to use strings, nor are you allowed to use functions that use
strings (num2str or str2num).
Hint: The rem function would be really useful here.
Part 3a
Write a vec2num function that does the opposite of the num2vec function: it
takes a vector of digits and converts it into a number. Hint: This function must
do the opposite operations as the num2vec function, and it must do them in
the opposite order.
n = vec2num([9 8 7 6 5])
n =
98765
class(n)
ans =
double
size(n)
ans =
1 1
Part 3b
Write a second vec2num function (call it vec2num2) that does the same thing
that vec2num does, but it uses a loop to create the number. In this function
you are not allowed to use strings, nor are you allowed to use functions that
use strings (num2str or str2num).