c++ very strange numbers

Question

void mult(int number2, int argc, char** argv)
{
    for (int i = 4; i < argc; i++) {
        double number3 = atof(argv[i]);
        double number2 = number2 * number3;
        cout << number2 << endl;
    }
}

my input is

./calc1 * 1 2 4 5 6

when I run this program ,output is :

2.07418e-317
4.14837e-317
1.65935e-316
8.29674e-316
4.97804e-315

ı am using gedit.

`double number2=number2*number3;` typo, the first number on the RHS should be `number3`. — Baum mit Augen, Feb 26 '17 at 15:28

Yousaf · Answer 1 · 2017-02-26T15:33:10.423

1

double number2 = number2 * number3;

you need to initialize number2 with some value otherwise it contains a garbage value which is getting multiplied with number3

split above statement into two statements

double number2 = /*some value to initialize number2*/;
number2 *= number3;    //now perform multiplication

Additionally, number2 is being passed into function mult as an argument, and you are also declaring a new variable with the same name number2 inside mult function.

edited Feb 26 '17 at 15:33

answered Feb 26 '17 at 15:29

Yousaf

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sorry It is my mistake I call this function with int number1=1; mult(number1,argc,argv); – Mustafa Savran Feb 26 '17 at 15:33

score 0 · Answer 2 · edited May 23 '17 at 12:25

0

double number2 = number2 * number3;

You're accessing number2 before initializing it, which causes undefined behavior.

edited May 23 '17 at 12:25

Community

1
1

answered Feb 26 '17 at 15:28

Emil Laine

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c++ very strange numbers

2 Answers2