0 and 1 in exponents

Algebra Level 3

How many statement(s) below is/are correct?

Statement 1: $1^x = 1$ for all real values of $x$ .
Statement 2: $x^1 = 1$ for all real values of $x$ .
Statement 3: $0^x = 0$ for all real values of $x$ .
Statement 4: $x^0 = 1$ for all real values of $x$ .