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do {

This loop will print each digit starting from the last digit, and ending with the first digit of the integer "num"

We need to process the digits of the integer from right to left and print them.

do {

This loop will print each digit starting from the last digit, and ending with the first digit of the integer "num"

Therefore, we need to use a loop structure.

do {

This loop will print each digit starting from the last digit, and ending with the first digit of the integer "num"

In this program, we do this by using a do loop.

do {

This loop will print each digit starting from the last digit, and ending with the first digit of the integer "num"

The do loop is more appropriate than a while loop because a positive integer always has at least one digit which results in the body of the loop performing at least once.

System.out.println(num % 10);

This line performs a modulus calculation that gets the last digit from the integer "num" and prints that digit.

Each printed digit is followed by the line separator (e.g. '\n') at the end.

System.out.println(num % 10);

This line performs a modulus calculation that gets the last digit from the integer "num" and prints that digit.

We need to extract the last digit in the 1's position of the integer.

System.out.println(num % 10);

This line performs a modulus calculation that gets the last digit from the integer "num" and prints that digit.

For example, if the integer is 1234, we want to extract the digit 4 that is in 1's position of the integer.

System.out.println(num % 10);

This line performs a modulus calculation that gets the last digit from the integer "num" and prints that digit.

We do this by calculating the remainder of the division of the integer by 10.

System.out.println(num % 10);

This line performs a modulus calculation that gets the last digit from the integer "num" and prints that digit.

Then, this statement prints the last digit of the integer to the standard output stream.

num = num / 10;

This divides the integer "num" by 10 so that the next time through the loop it gets the next digit in "num"

Therefore, this division will remove the digit that we processed (lastDigit) and we can move on to the next digit.

num = num / 10;

This divides the integer "num" by 10 so that the next time through the loop it gets the next digit in "num"

We truncate the extracted digit that we processed from the original integer by dividing the integer by 10.

num = num / 10;

This divides the integer "num" by 10 so that the next time through the loop it gets the next digit in "num"

Note that this statement performs an integer division because both operand of the / operator are integer.

} while (num > 0);

This is the second part of the do-while loop.

We need to check for termination conditions to avoid infinite loops.

} while (num > 0);

This is the second part of the do-while loop.

The loop should terminate when we run out of digits to process.

} while (num > 0);

This is the second part of the do-while loop.

We could check whether the are more digits left by checking whether the variable num, which gets updated in the body of the do loop, is greater than zero.

} while (num > 0);

This is the second part of the do-while loop.

If variable num is greater than zero, then it must have at least one digit, and in that case, the body of the do loop will be repeated again.

} while (num > 0);

This is the second part of the do-while loop.

The body of the while loop should repeat as long as there are more digits left that we have not processed yet.

} while (num > 0);

It makes sure this loop continues to loop through while the integer "num" is greater than 0.

We need to check for termination conditions to avoid infinite loops.

} while (num > 0);

It makes sure this loop continues to loop through while the integer "num" is greater than 0.

The loop should terminate when we run out of digits to process.

} while (num > 0);

It makes sure this loop continues to loop through while the integer "num" is greater than 0.

We could check whether the are more digits left by checking whether the variable num, which gets updated in the body of the do loop, is greater than zero.

} while (num > 0);

It makes sure this loop continues to loop through while the integer "num" is greater than 0.

If variable num is greater than zero, then it must have at least one digit, and in that case, the body of the do loop will be repeated again.

} while (num > 0);

It makes sure this loop continues to loop through while the integer "num" is greater than 0.

The body of the while loop should repeat as long as there are more digits left that we have not processed yet.

Scanner scan = new Scanner(System.in);

Allows the user to send input to the machine

To read the input values from the user, we need to define a Scanner object.

Scanner scan = new Scanner(System.in);

Allows the user to send input to the machine

We need to read and process the values that the user enters.

System.out.println("Enter the phone age in years:");

Asks the user by printing a line that says to "enter the phone age in years:"

We prompt the user to enter the phone age in years.

int phoneAge = scan.nextInt();

This line sets the int "phoneAge" to the next input it receives from the user.

We read the phone age by calling the nextInt() method because this input is an integer.

int phoneAge = scan.nextInt();

This line sets the int "phoneAge" to the next input it receives from the user.

We need to read the phone age that the user enters and store it in a variable.

System.out.println("Enter whether the phone is broken (true or false):");

Prints the statement "Enter whether the phone is broken (true or false):" on the machine.

We prompt the user to enter whether the phone is broken.

boolean isBroken = scan.nextBoolean();

Sets the boolean "isBroken" to the next input it receives from the user

We need to read whether the phone is broken and store it in a variable.

boolean isBroken = scan.nextBoolean();

Sets the boolean "isBroken" to the next input it receives from the user

The variable isBroken is true when the phone is broken, and false otherwise.

boolean isBroken = scan.nextBoolean();

Sets the boolean "isBroken" to the next input it receives from the user

We read whether the phone is broken by calling the nextBoolean() method because this input is a boolean.

scan.close();

Stops allowing the user to send input

We close the scanner as we do not want to process any input from the user in the rest of the program.

boolean needPhone = isBroken || phoneAge >= 3;

Sets needPhone to true if isBroken is true or phoneAge is greater than 3.

We use the || operator (called or) to combine the two conditions.

boolean needPhone = isBroken || phoneAge >= 3;

Sets needPhone to true if isBroken is true or phoneAge is greater than 3.

The first condition is to test if the phone is broken and the second condition is to test if the phone age is at least 3 years old.

boolean needPhone = isBroken || phoneAge >= 3;

Sets needPhone to true if isBroken is true or phoneAge is greater than 3.

We need two conditions to determine if it is the time for a new phone.

boolean needPhone = isBroken || phoneAge >= 3;

Otherwise it sets needPhone to false.

We use the || operator (called or) to combine the two conditions.

boolean needPhone = isBroken || phoneAge >= 3;

Otherwise it sets needPhone to false.

The first condition is to test if the phone is broken and the second condition is to test if the phone age is at least 3 years old.

boolean needPhone = isBroken || phoneAge >= 3;

Otherwise it sets needPhone to false.

We need two conditions to determine if it is the time for a new phone.

System.out.println(needPhone);

Prints out the needPhone boolean that was set in the previous line

This statement prints true/false depending on whether it is time to buy a new phone.

System.out.println(needPhone);

Prints out the needPhone boolean that was set in the previous line

The printed value is followed by an end-of-line character in the end.

System.out.println(needPhone);

Prints out the needPhone boolean that was set in the previous line

This statement prints true/false depending on whether it is time to buy a new phone.

System.out.println(needPhone);

Prints out the needPhone boolean that was set in the previous line

The printed value is followed by an end-of-line character in the end.

String fullName = "John Smith"

Sets the fullName string to John Smith

We define a string variable to hold the name.

String firstInitial = fullName.substring(0, 1);

Sets the firstInitial string to the first character in the fullName String.

We need to extract the first letter from the first name.

String firstInitial = fullName.substring(0, 1);

Sets the firstInitial string to the first character in the fullName String.

We do this by calling the substring(0,1) method.

String lastInitial = fullName.substring(5, 6);

Sets the lastInitial string to the 6th character in the fullName string.

We need to extract the first letter from the last name.

String lastInitial = fullName.substring(5, 6);

Sets the lastInitial string to the 6th character in the fullName string.

We do this by calling the substring(5,6) method.

String initials = firstInitial + lastInitial;

Sets the initials string to the firstInitial and lastInitial strings combined.

This statements concatenates the extracted initials and store the result in the string initials.

System.out.println(initials);

Prints out the string initials to the machine

This statement prints the initials to the default standard output stream.

System.out.println(initials);

Prints out the string initials to the machine

The printed value is followed by the end-of-line character at the end.

int[] values = {5, 8, 4, 78, 95, 12, 1, 0, 6, 35, 46};

Sets an integer array that has a set of 5 values: 5, -4, 78, 95, 12

We define array values to hold the specified numbers.

int[] values = {5, 8, 4, 78, 95, 12, 1, 0, 6, 35, 46};

Sets an integer array that has a set of 5 values: 5, -4, 78, 95, 12

We initialize the array by separating elements with a comma and enclosing the collection in braces { }.

int maxValue = values[0];

Sets the maxValue int to the first value in the array

We need variable maxValue to store the maximum value of the array.

int maxValue = values[0];

Sets the maxValue int to the first value in the array

We initialize this variable by the first value in the array because we initially assume that the first value is the maximum.

for (int i = 1; i < values.length; i++) {

Starts a for loop that loops through each of the values in the values array starting from the second variable in the array.

We use a for loop to iterate over the remaining array indexes and search for the maximum value.

for (int i = 1; i < values.length; i++) {

Starts a for loop that loops through each of the values in the values array starting from the second variable in the array.

We need the array indexes to start at 1 with every integer number up to but not including the array length.

if (values[i] > maxValue) {

If the current value in the loop is greater than maxValue, enter into the if statement.

We need to compare the value at the index i of the array with the maximum value stored in variable maxValue.

if (values[i] > maxValue) {

If the current value in the loop is greater than maxValue, enter into the if statement.

If the value at that index is larger than the maximum value, then we need to set the maximum value to the value of the element at index i.

maxValue = values[i];

Sets maxValue to the current index in the values array

This statement sets the maximum value to value of the element at index i of the array.

System.out.println("Maximum value: " + maxValue);

Prints out the statement "Maximum value: " and maxValue variable

This statement prints the maximum value of the array to the default standard output stream.

System.out.println("Maximum value: " + maxValue);

Prints out the statement "Maximum value: " and maxValue variable

This statement prints the maximum value of the array to the default standard output stream.

Scanner scan = new Scanner(System.in);

Create a new scanner object with args of input.

To read the input value from the user, we need to define a Scanner object.

Scanner scan = new Scanner(System.in);

Create a new scanner object with args of input.

We need to read and process the integer that the user enters.

System.out.println("Enter an integer: ");

It is asking the user for an integer.

We prompt the user to enter an integer.

int num = scan.nextInt();

It is assigning the value of the next entered integer to "num" variable.

We read the input integer by calling the nextInt() method because this input is an integer.

int num = scan.nextInt();

It is assigning the value of the next entered integer to "num" variable.

We need to read the integer that the user enters and store it in a variable.

scan.close();

It is closing the the object to accepting further input.

We close the scanner as we do not want to process any input from the user in the rest of the program.

if ( num > 0 ) {

It is checking if the integer that was entered is greater than 0.

If the integer is neither positive nor negative, then we could conclude that the integer is zero.

if ( num > 0 ) {

It is checking if the integer that was entered is greater than 0.

The conditions that tests for the integer's sign are mutually exclusive (i.e., one and only one of the conditions can be true); therefore, their order does not matter.

if ( num > 0 ) {

It is checking if the integer that was entered is greater than 0.

To determine the sign of the integer, we need to perform two tests: one for determining whether the integer is positive and one for determining whether the integer is negative.

if ( num > 0 ) {

It is checking if the integer that was entered is greater than 0.

Also, it is better to use if-else if statements instead of sequential if statements because an integer has only one sign and once we find the sign, we don't need to perform more tests.

if ( num > 0 ) {

It is checking if the integer that was entered is greater than 0.

If both of these tests fail, then we could conclude that the integer is zero.

System.out.println("The integer is positivie.");

It is printing out that the integer is positive.

This statement prints that the integer is positive.

System.out.println("The integer is positivie.");

It is printing out that the integer is positive.

The printed text is followed by the end-of-line character at the end.

} else if ( num < 0 ) {

If it wasn't positive, it is checking if the integer was negative.

If the first test fails (i.e., when the integer is not positive), we need to test if the integer is negative.

System.out.println("The integer is negative.");

It is printing out that the integer was negative.

The printed text is followed by the end-of-line character at the end.

System.out.println("The integer is negative.");

It is printing out that the integer was negative.

This statement prints that the integer is negative.

} else {

If it is neither negative nor positive then do the following code.

We need to end the above if-else if statements with an else statement that its body is executed when none of the above tests are true, that is when the integer is zero.

System.out.println("The integer is zero.");

Print out that the integer is 0.

The printed text is followed by the end-of-line character at the end.

System.out.println("The integer is zero.");

Print out that the integer is 0.

This statement prints that the integer is zero.

int [] arr = { 1, 2, 3};

Making an array that contains integer value of 1 at position 0, integer value of 2 at position 1, and integer value of 3 at position 2

We initialize the array of type int to hold the specified numbers.

int [] arr = { 1, 2, 3};

Making an array that contains integer value of 1 at position 0, integer value of 2 at position 1, and integer value of 3 at position 2

We initialize the array by separating elements with a comma and enclosing the collection in braces { }.

int [] arr = { 1, 2, 3};

Making an array that contains integer value of 1 at position 0, integer value of 2 at position 1, and integer value of 3 at position 2.

We initialize the array of type int to hold the specified numbers.

int [] arr = { 1, 2, 3};

Making an array that contains integer value of 1 at position 0, integer value of 2 at position 1, and integer value of 3 at position 2.

We initialize the array by separating elements with a comma and enclosing the collection in braces { }.

for ( int i = 0; i < arr.length; i++ ) {

Loop through the array, starting at 0, increment the position by 1 until reaching the end of the array.

We want to iterate over the array and increment each element in the array by 1.

for ( int i = 0; i < arr.length; i++ ) {

Loop through the array, starting at 0, increment the position by 1 until reaching the end of the array.

To really change the array as we march across it, we need to use indexes so we can assign an updated value to each position as we go.

for ( int i = 0; i < arr.length; i++ ) {

Loop through the array, starting at 0, increment the position by 1 until reaching the end of the array.

We need the array indexes to start at 0 (array indexes start from 0) with every integer number up to but not including the array length.

arr[i] += 1;

Add 1 to the value in the array at position i.

This statement increments the element at the index i of the array by 1.

Scanner scan = new Scanner(System.in);

Allows the user to type input on the machine

To read the input value from the user, we need to define a Scanner object.

Scanner scan = new Scanner(System.in);

Allows the user to type input on the machine

We need to read and process the value that the user enters.

int seconds = scan.nextInt();

Sets the int seconds to the next input from the user

We need to read the seconds that the user enters and store it in a variable.

int seconds = scan.nextInt();

Sets the int seconds to the next input from the user

We read the seconds by calling the nextInt() method because this input is an integer.

System.out.println("Enter an integer for seconds: ");

Prints the line "Enter an integer for seconds: "

We prompt the user to enter the seconds.

scan.close();

Disables the user's ability to type input to the machine

We close the scanner as we do not want to process any input from the user in the rest of the program.

int minutes = seconds / 60;

Sets the int minutes to seconds divided by 60

To obtain the minutes in seconds, we divide the seconds by 60 because there are 60 seconds in a minute.

int minutes = seconds / 60;

Sets the int minutes to seconds divided by 60

Note that since both operands of division operator are integer, the fractional part of the result is truncated, if there is any.

int remainingSeconds = seconds % 60;

Sets remaining seconds to seconds modulus 60.

This is because there are 60 seconds in a minute.

int remainingSeconds = seconds % 60;

Sets remaining seconds to seconds modulus 60.

Note that the % operator returns the remainder of the division.

int remainingSeconds = seconds % 60;

Sets remaining seconds to seconds modulus 60.

To obtain the remaining seconds after taking away the minutes, we have to take the remainder of the seconds divided by 60.

int remainingSeconds = seconds % 60;

The modulus function gets the remainder.

This is because there are 60 seconds in a minute.