Need help with critical thinking java questions:

1. Explain the scope of each of the variables in the code below:

public class ScopeExample {

public static void method1() {

int var3;

for (int var4 = 0; var4 < 2; var4++) {

var3 +=1;

}

}

}

End of code

2.Find and explain the error in the code below:

public class MethodCallExample {

public static int doSomething() {

return(5);

}

}

public static void main(String[] args) {

int num;

doSomething();

num = doSomething():

}