Intro to Java Day 3 / Loops 1

DAY 3 Java Language Specifications Conditional Loops while do for References: JavaNotes7 pdf bookJavaNotes7 pdf book

WHILE STATEMENT 3 … while ( ) … The is called the “Continuation Condition” … while ( ) … The is called the “Continuation Condition”

WHILE EXAMPLE Java Code: … int i; i = 0; while ( i < 10 ) { System.out.println(i); i = i + 1; } … Java Code: … int i; i = 0; while ( i < 10 ) { System.out.println(i); i = i + 1; } … 4 Output: Output:

WHILE LOOP NESTING Java Code: … int i, j; i = 0; j = 0; while ( i < 10 ) { j = 0; System.out.printf("i=%d:", i ); while ( j < 2 ) { System.out.printf(" j=%d", j); j = j + 1; } System.out.printf(".\n"); i = i + 1; } … Java Code: … int i, j; i = 0; j = 0; while ( i < 10 ) { j = 0; System.out.printf("i=%d:", i ); while ( j < 2 ) { System.out.printf(" j=%d", j); j = j + 1; } System.out.printf(".\n"); i = i + 1; } … 5 Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1. Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1.

DO WHILE STATEMENT 6 … do { } while ( condition ); … int i = 0; do { i = i + 1; } while ( i < 10 ); // What is the value of i … do { } while ( condition ); … int i = 0; do { i = i + 1; } while ( i < 10 ); // What is the value of i …

DO WHILE LOOP NESTING Java Code: … int i, j; i = 0; j = 0; do { j = 0; System.out.printf("i=%d:", i); do { System.out.printf(" j=%d", j); j = j + 1; } while (j < 2); System.out.printf(".\n"); i = i + 1; } while (i < 10); … Java Code: … int i, j; i = 0; j = 0; do { j = 0; System.out.printf("i=%d:", i); do { System.out.printf(" j=%d", j); j = j + 1; } while (j < 2); System.out.printf(".\n"); i = i + 1; } while (i < 10); … 7 Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1. Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1.

FOR STATEMENT 8 … for ( ; ; ){ }; … int myvar = 10; for (int i=0; i<10; i++) { myvar = myvar + i; } // what is the value of myvar ? … for ( ; ; ){ }; … int myvar = 10; for (int i=0; i<10; i++) { myvar = myvar + i; } // what is the value of myvar ?

FOR LOOP NESTING #1 Java Code: … for ( int i=0; i<10; i++ ) { System.out.printf("i=%d:", i); for ( int j=0; j<2; j++ ) { System.out.printf(" j=%d", j); } System.out.printf(".\n"); } … Java Code: … for ( int i=0; i<10; i++ ) { System.out.printf("i=%d:", i); for ( int j=0; j<2; j++ ) { System.out.printf(" j=%d", j); } System.out.printf(".\n"); } … 9 Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1. Output: i=0: j=0 j=1. i=1: j=0 j=1. i=2: j=0 j=1. i=3: j=0 j=1. i=4: j=0 j=1. i=5: j=0 j=1. i=6: j=0 j=1. i=7: j=0 j=1. i=8: j=0 j=1. i=9: j=0 j=1.

FOR LOOP NESTING #2 Java Code: … for ( int i=0; i<10; i++ ) { System.out.printf("i=%d:", i); for ( int j=3; j>0; j-- ) { System.out.printf(" j=%d", j); } System.out.printf(".\n"); } … Java Code: … for ( int i=0; i<10; i++ ) { System.out.printf("i=%d:", i); for ( int j=3; j>0; j-- ) { System.out.printf(" j=%d", j); } System.out.printf(".\n"); } … 10 Output: i=0: j=3 j=2 j=1. i=1: j=3 j=2 j=1. i=2: j=3 j=2 j=1. i=3: j=3 j=2 j=1. i=4: j=3 j=2 j=1. i=5: j=3 j=2 j=1. i=6: j=3 j=2 j=1. i=7: j=3 j=2 j=1. i=8: j=3 j=2 j=1. i=9: j=3 j=2 j=1. Output: i=0: j=3 j=2 j=1. i=1: j=3 j=2 j=1. i=2: j=3 j=2 j=1. i=3: j=3 j=2 j=1. i=4: j=3 j=2 j=1. i=5: j=3 j=2 j=1. i=6: j=3 j=2 j=1. i=7: j=3 j=2 j=1. i=8: j=3 j=2 j=1. i=9: j=3 j=2 j=1.

ASSIGNMENT Create 1 or 2 programs using while and for loop, that print only the odd numbers between 0 and 100. example: … 99 Advanced: Print an asterisk “*”, next to the numbers that are divisible by 5 example: 1 3 5* 7 9 … 99

LINKS & REFERENCES Intro to Java Language Web Page Oracle Java Language Specifications JavaNotes-7 pdf book linked.pdf linked.pdf 12