code for solve power with out use Math class

Answer 1

// (not really optimized way:)

int myNum = 5;
int pow = 2;

int base = myNum;
for (int i = 1; i < pow: i++)
myNum *= base;

//As method:
public int pow(int num, int pow) {
int base = num;
for (int i = 1; i < pow; i++)
num *= base;
return num;
}
int i25 = pow(5, 2);
//You can replace the int type to float, double, what you want.

A bit of optimalization:

public int pow(int base, int pow) {
while (pow % 2 == 0) {
base *= base;
pow /= 2;
}
int num = base;
for (int i = 1; i < pow; i++)
num *= base;
return num;
}

Answer 2

I wonder what would be the reason to reinvent the wheel? since this solution does not cover any exceptions like x^0 always equals 1, x^1 always equals x, x^-1 always equals 1/x and so on...