Transcript Nesting control structures

Lec 5
Nested Control Structures
Calculating the sum or average
sum num
int sum = 0;
int k = 0, num;
while ( k < 5) {
num = scan.nextInt();
sum = sum + num;
k = k + 1;
}
...println("sum is " + sum);
...println("avg is " + sum/5.0);
k
k < 10 Console
Nesting
• The idea of nesting is to put one thing inside
of another:
– nested: ( [ { } { } ] { } )
– not nested: ( ) [ ] { } [ ]
– NOT nested: ( [ { ) ] }
Nesting control structures
• We have seen several control structures
– do loops
– while loops
– if statements (including compound if statements
with else if and else )
• We can nest any of these structures inside
another to get different behaviors
While loop with if inside
int i = 0;
while ( i < 3) {
if ( i == 0) {
...println("zero");
}
else {
...println( i );
}
i = i + 1;
}
i
i<3
i==0
Console
While loop with if inside
big
num i
int i = 0, big=0, num;
while ( i < 5) {
num = scan.nextInt();
if ( num > 50) {
big = big+1;
}
i = i + 1;
}
...println("number of big: " + big);
i<5
Console
Work on Loop Drills in class
• Due next Tuesday
• you may finish today
• these are exam style questions so make sure
you master them
Lab 5
• Guessing Game
• pick a random number and store it
• Do Loop:
– get user guess
– if guess is high or low, say it
– when guess is correct leave loop