Is it bad practice to declare variable and changing it in and if statement?

When coding I noticed I started to get into a habit of not using if-else statements when the else block only has one line of code. For example, if I have code that can be solved like this:

public Person(int initialAge) {
    if(initialAge < 0){
        System.out.println("Age is not valid, setting age to 0.");
        age = 0;
    }
    else{
        age = initialAge;
    }
   }

I will instead remove the else statement entirely to cut down on a few lines of code. This results in my code looking more like this:

public Person(int initialAge) {
    age = initialAge;
    if(initialAge < 0){
        System.out.println("Age is not valid, setting age to 0.");
        age = 0;
    }
   }

I'm wondering if this is a bad coding habit to get into and if I should break out of this coding habit or if it'll be fine to continue doing this. Would doing this be a bigger issue down the line when I get onto more complex programs?