Converting strings into integers

[Misko]

Hi,

I'm a newbie in the matter of C++.
Now i'm trying to convert a text from a string (like str = "123") into an int-variable.
In Java i've used parseInt for this function, but i can't find the C++-equivalence.
I rather use a string and not a char-array...

Idea someone?

Thx in advance,
Misko

[Meetee]

Hi,

I'm a newbie in the matter of C++.
Now i'm trying to convert a text from a string (like str = "123") into an int-variable.
In Java i've used parseInt for this function, but i can't find the C++-equivalence.
I rather use a string and not a char-array...

Idea someone?

Thx in advance,
Misko

Hi Misko,

You can use atoi function for that.
Usage is like this:

int value = atoi ( const char * str );

This requires char array as const char * is passed as a parameter.

Regards

[weaknessforcats]

atoi() is deprecated in C++.

Use a stringstream.

int result;
string str("123");
stringstream ss;
ss << str;
ss >> result;
 

[PieCook]

I was just about to suggest a custom-made function, but the other ones look far better. I was going to do something like this:

 
int sum = 0;
int length = strlen(str);
for (i = length - 1; i >= 0; i--)
    sum += str[i] * pow(10, length - i);
 
 

I did not run the code, so it might have a bug or two, but you get the idea.