I am having trouble using tolower() in C++

Question

When I try to use tolower on a string, rather than making the letters lowercase, the program converts them to random symbols. Here is my code:

#include <iostream>
#include <locale>
using namespace std;

int main()
{
    string hi= "thTSMSdjNnJlJjnJJKn";
    for (int i=0; i<hi.length(); i++)
    {
        hi[i]+=tolower(hi[i]);
        cout << hi[i];
    }
}

This is the output: Þð╚ã║ã╚È╝▄┤Ï┤È▄┤┤Â▄

What is wrong with it? This isn't the actual code that I want to use tolower on but I just put it in a separate example so it was more clear. I don't mind using to upper either but the main thing is that I get all the letters in the string to be the same case.

you don't `#include ` at first , second `hi[i]=tolower(hi[i]);` should work — Mohsen_Fatemi, Jan 16 '17 at 09:32
ok thanks, If someone just puts that in an answer I can vote it best answer because thats all I needed. — , Jan 16 '17 at 09:34
For standard compliance it should be either `tolower(hi[i],locale())` or `tolower(static_cast(hi[i]))`. Modern compilers all allow your usage though as it is such a common mistake. — M.M, Jan 16 '17 at 10:46

score 3 · Answer 1 · answered Jan 16 '17 at 09:43

3

There's a typo in the for loop:

hi[i] += tolower(hi[i]);

should be

hi[i] = tolower(hi[i]);

Also, your code is missing #include <string>

answered Jan 16 '17 at 09:43

roalz

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I am having trouble using tolower() in C++

1 Answers1