How can i know the length of an integer?

Question

suppose an integer i=124682;
how can i know that how many digits this integer has?

Answer 1

i would do this:

int digits, num = 124682;

for (digits = 0; num; digits++)
num /= 10;

cout << digits << '\n';

Answer 2

// my one-liner to count digits using a mathematical approach
#include <math.h>
.
.
.
int i = 124682, nDigits;
nDigits = floor(log10(abs(i == 0 ? 1 : i))) + 1;

The code is unreadable and relies on a mathematical "trick", so I don't strongly recommend this approach.
Here is sample code that uses it:
https://code.sololearn.com/c3EwDn9O4Gbg/?ref=app