Code Line
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57 values
User Explanation
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692 values
Line-Explanation in PCEX
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Annotation Score
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do {
The code in the body of the do will first execute and continue to execute while the while function is true.
We need to process the digits of the integer from right to left and print them.
1
do {
The code in the body of the do will first execute and continue to execute while the while function is true.
Therefore, we need to use a loop structure.
1
do {
The code in the body of the do will first execute and continue to execute while the while function is true.
In this program, we do this by using a do loop.
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do {
The code in the body of the do will first execute and continue to execute while the while function is true.
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.
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} while (num > 0);
This is the continuation test.
We need to check for termination conditions to avoid infinite loops.
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} while (num > 0);
This is the continuation test.
The loop should terminate when we run out of digits to process.
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} while (num > 0);
This is the continuation test.
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.
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} while (num > 0);
This is the continuation test.
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.
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} while (num > 0);
This is the continuation test.
The body of the while loop should repeat as long as there are more digits left that we have not processed yet.
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} while (num > 0);
This is what drives the loop.
We need to check for termination conditions to avoid infinite loops.
2
} while (num > 0);
This is what drives the loop.
The loop should terminate when we run out of digits to process.
2
} while (num > 0);
This is what drives the 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.
1
} while (num > 0);
This is what drives the 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.
1
} while (num > 0);
This is what drives the loop.
The body of the while loop should repeat as long as there are more digits left that we have not processed yet.
1
} while (num > 0);
As long as the number doesn't reduce to 0 , we keep running this loop.
We need to check for termination conditions to avoid infinite loops.
2
} while (num > 0);
As long as the number doesn't reduce to 0 , we keep running this loop.
The loop should terminate when we run out of digits to process.
2
} while (num > 0);
As long as the number doesn't reduce to 0 , we keep running this 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.
3
} while (num > 0);
As long as the number doesn't reduce to 0 , we keep running this 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.
2
} while (num > 0);
As long as the number doesn't reduce to 0 , we keep running this loop.
The body of the while loop should repeat as long as there are more digits left that we have not processed yet.
4
} while (num > 0);
The loop is terminated once all the digits have been printed and the number reduces to 0.
We need to check for termination conditions to avoid infinite loops.
2
} while (num > 0);
The loop is terminated once all the digits have been printed and the number reduces to 0.
The loop should terminate when we run out of digits to process.
3
} while (num > 0);
The loop is terminated once all the digits have been printed and the number reduces to 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.
2
} while (num > 0);
The loop is terminated once all the digits have been printed and the number reduces to 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.
2
} while (num > 0);
The loop is terminated once all the digits have been printed and the number reduces to 0.
The body of the while loop should repeat as long as there are more digits left that we have not processed yet.
3
System.out.println(num % 10);
This line prints out what right most integer of the current num by using the modulus function.
Each printed digit is followed by the line separator (e.g. '\n') at the end.
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System.out.println(num % 10);
This line prints out what right most integer of the current num by using the modulus function.
We need to extract the last digit in the 1's position of the integer.
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System.out.println(num % 10);
This line prints out what right most integer of the current num by using the modulus function.
For example, if the integer is 1234, we want to extract the digit 4 that is in 1's position of the integer.
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System.out.println(num % 10);
This line prints out what right most integer of the current num by using the modulus function.
We do this by calculating the remainder of the division of the integer by 10.
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System.out.println(num % 10);
This line prints out what right most integer of the current num by using the modulus function.
Then, this statement prints the last digit of the integer to the standard output stream.
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int num = 1234;
This saves the integer, whose digits will be printed from right to left, in a variable called num.
We need variable num to store the integer that we want to print its digits.
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num = num / 10;
This will update the new num by removing the right most digit of the current num.
Therefore, this division will remove the digit that we processed (lastDigit) and we can move on to the next digit.
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num = num / 10;
This will update the new num by removing the right most digit of the current num.
We truncate the extracted digit that we processed from the original integer by dividing the integer by 10.
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num = num / 10;
This will update the new num by removing the right most digit of the current num.
Note that this statement performs an integer division because both operand of the / operator are integer.
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} while (num > 0);
This allows the code in the do body to execute while num is greater than 0.
We need to check for termination conditions to avoid infinite loops.
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} while (num > 0);
This allows the code in the do body to execute while num is greater than 0.
The loop should terminate when we run out of digits to process.
2
} while (num > 0);
This allows the code in the do body to execute while 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.
2
} while (num > 0);
This allows the code in the do body to execute while 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.
2
} while (num > 0);
This allows the code in the do body to execute while 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.
2
Scanner scan = new Scanner(System.in);
We created a scanner object, which is the object required to take input from user.
To read the input values from the user, we need to define a Scanner object.
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Scanner scan = new Scanner(System.in);
We created a scanner object, which is the object required to take input from user.
We need to read and process the values that the user enters.
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Scanner scan = new Scanner(System.in);
This creates a Scanner object called scan so that it could be used to retrieve data from user input.
To read the input values from the user, we need to define a Scanner object.
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Scanner scan = new Scanner(System.in);
This creates a Scanner object called scan so that it could be used to retrieve data from user input.
We need to read and process the values that the user enters.
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System.out.println("Enter the phone age in years:");
This prints out: "Enter the phone age in years:" so that the user will know what to enter.
We prompt the user to enter the phone age in years.
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System.out.println("Enter the phone age in years:");
We print output on the screen with the message "Enter the phone age in years", asking the user to input phone age.
We prompt the user to enter the phone age in years.
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int phoneAge = scan.nextInt();
This saves the user input in a variable called phone age so that the program can test whether its time to get a new phone.
We read the phone age by calling the nextInt() method because this input is an integer.
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int phoneAge = scan.nextInt();
This saves the user input in a variable called phone age so that the program can test whether its time to get a new phone.
We need to read the phone age that the user enters and store it in a variable.
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System.out.println("Enter whether the phone is broken (true or false):");
This prints out "Enter whether the phone is broken (true or false):" so that the user knows what to enter.
We prompt the user to enter whether the phone is broken.
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int phoneAge = scan.nextInt();
We initialize an integer variable named phoneAge, and scan the user input and store it in it.
We read the phone age by calling the nextInt() method because this input is an integer.
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int phoneAge = scan.nextInt();
We initialize an integer variable named phoneAge, and scan the user input and store it in it.
We need to read the phone age that the user enters and store it in a variable.
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boolean isBroken = scan.nextBoolean();
This scans the new input that the user just submitted and saves it into a boolean variable called isBroken.
We need to read whether the phone is broken and store it in a variable.
3
boolean isBroken = scan.nextBoolean();
This scans the new input that the user just submitted and saves it into a boolean variable called isBroken.
The variable isBroken is true when the phone is broken, and false otherwise.
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boolean isBroken = scan.nextBoolean();
This scans the new input that the user just submitted and saves it into a boolean variable called isBroken.
We read whether the phone is broken by calling the nextBoolean() method because this input is a boolean.
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scan.close();
This closes the scan object since it will no longer be used.
We close the scanner as we do not want to process any input from the user in the rest of the program.
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System.out.println("Enter whether the phone is broken (true or false):");
We print message to the user, asking to enter whether the phone has been broken or not.
We prompt the user to enter whether the phone is broken.
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System.out.println("Enter whether the phone is broken (true or false):");
The input should be either True or False.
We prompt the user to enter whether the phone is broken.
1
boolean isBroken = scan.nextBoolean();
we declare a Boolean variable isBroken and scan the user input and store it in this variable.
We need to read whether the phone is broken and store it in a variable.
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boolean isBroken = scan.nextBoolean();
we declare a Boolean variable isBroken and scan the user input and store it in this variable.
The variable isBroken is true when the phone is broken, and false otherwise.
1
boolean isBroken = scan.nextBoolean();
we declare a Boolean variable isBroken and scan the user input and store it in this variable.
We read whether the phone is broken by calling the nextBoolean() method because this input is a boolean.
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boolean needPhone = isBroken || phoneAge >= 3;
This will save true to the variable needPhone if either the phone is 3 or more years old or if the user entered true if the phone is broken, else it will save needPhone as false.
We use the || operator (called or) to combine the two conditions.
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boolean needPhone = isBroken || phoneAge >= 3;
This will save true to the variable needPhone if either the phone is 3 or more years old or if the user entered true if the phone is broken, else it will save needPhone as 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.
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boolean needPhone = isBroken || phoneAge >= 3;
This will save true to the variable needPhone if either the phone is 3 or more years old or if the user entered true if the phone is broken, else it will save needPhone as false.
We need two conditions to determine if it is the time for a new phone.
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scan.close();
After we are done taking input, we close the scanner object using this line.
We close the scanner as we do not want to process any input from the user in the rest of the program.
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System.out.println(needPhone);
This prints out true or false based on the information given to the program by the user.
This statement prints true/false depending on whether it is time to buy a new phone.
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System.out.println(needPhone);
This prints out true or false based on the information given to the program by the user.
The printed value is followed by an end-of-line character in the end.
1
boolean needPhone = isBroken || phoneAge >= 3;
if the phone is broken or age is more than 3 then bolean true will be stored in the variable.
We use the || operator (called or) to combine the two conditions.
2
boolean needPhone = isBroken || phoneAge >= 3;
if the phone is broken or age is more than 3 then bolean true will be stored in the variable.
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.
3
boolean needPhone = isBroken || phoneAge >= 3;
if the phone is broken or age is more than 3 then bolean true will be stored in the variable.
We need two conditions to determine if it is the time for a new phone.
3
Scanner scan = new Scanner(System.in);
We create a scanner object named scan.
To read the input value from the user, we need to define a Scanner object.
3
Scanner scan = new Scanner(System.in);
We create a scanner object named scan.
We need to read and process the integer that the user enters.
2
Scanner scan = new Scanner(System.in);
It will be used to take input from user.
To read the input value from the user, we need to define a Scanner object.
3
Scanner scan = new Scanner(System.in);
It will be used to take input from user.
We need to read and process the integer that the user enters.
3
System.out.println("Enter an integer: ");
We print to the user interface, "Enter an integer" asking the user to input an integer.
We prompt the user to enter an integer.
4
int num = scan.nextInt();
the scanner object scans the number as a string, reading one character at a time and converting it to an integer, using the method nextInt() and storing the result in the integer variable num.
We read the input integer by calling the nextInt() method because this input is an integer.
3
int num = scan.nextInt();
the scanner object scans the number as a string, reading one character at a time and converting it to an integer, using the method nextInt() and storing the result in the integer variable num.
We need to read the integer that the user enters and store it in a variable.
3
scan.close();
We then close the scanner object.
We close the scanner as we do not want to process any input from the user in the rest of the program.
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scan.close();
No more input needed.
We close the scanner as we do not want to process any input from the user in the rest of the program.
2
if ( num > 0 ) {
Beginning of an if statement , if num is greater than 0 then the code enclosed by if will be terminated.
If the integer is neither positive nor negative, then we could conclude that the integer is zero.
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if ( num > 0 ) {
Beginning of an if statement , if num is greater than 0 then the code enclosed by if will be terminated.
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.
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if ( num > 0 ) {
Beginning of an if statement , if num is greater than 0 then the code enclosed by if will be terminated.
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.
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if ( num > 0 ) {
Beginning of an if statement , if num is greater than 0 then the code enclosed by if will be terminated.
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.
2
if ( num > 0 ) {
Beginning of an if statement , if num is greater than 0 then the code enclosed by if will be terminated.
If both of these tests fail, then we could conclude that the integer is zero.
1
System.out.println("The integer is positivie.");
Once meeting the if criteria, this line of code prints to the user "The integer is positive" .
This statement prints that the integer is positive.
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System.out.println("The integer is positivie.");
Once meeting the if criteria, this line of code prints to the user "The integer is positive" .
The printed text is followed by the end-of-line character at the end.
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} else if ( num < 0 ) {
If the if criteria is not met, then the else if criteria is checked, that is , if the num is less than 0.
If the first test fails (i.e., when the integer is not positive), we need to test if the integer is negative.
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System.out.println("The integer is negative.");
if the else if criteria is met, the this line prints to the user, "The integer is negative".
The printed text is followed by the end-of-line character at the end.
1
System.out.println("The integer is negative.");
if the else if criteria is met, the this line prints to the user, "The integer is negative".
This statement prints that the integer is negative.
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System.out.println("The integer is negative.");
if the else if criteria is met, the this line prints to the user, "The integer is negative".
The printed text is followed by the end-of-line character at the end.
1
System.out.println("The integer is negative.");
if the else if criteria is met, the this line prints to the user, "The integer is negative".
This statement prints that the integer is negative.
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} else {
if none of the criteria meets then the code enclosed by else is executed, that is , it prints to the user "The integer is zero" .
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.
2
} else {
if none of the criteria meets then the code enclosed by else is executed.
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.
3
System.out.println("The integer is zero.");
If none of the criteria meets, then this line prints to the user "The integer is zero".
The printed text is followed by the end-of-line character at the end.
1
System.out.println("The integer is zero.");
If none of the criteria meets, then this line prints to the user "The integer is zero".
This statement prints that the integer is zero.
3
int [] arr = { 1, 2, 3};
we declare an integer array, with its elements initialized.
We initialize the array of type int to hold the specified numbers.
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int [] arr = { 1, 2, 3};
we declare an integer array, with its elements initialized.
We initialize the array by separating elements with a comma and enclosing the collection in braces { }.
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int [] arr = { 1, 2, 3};
Namely 1,2 and 3.
We initialize the array of type int to hold the specified numbers.
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int [] arr = { 1, 2, 3};
Namely 1,2 and 3.
We initialize the array by separating elements with a comma and enclosing the collection in braces { }.
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for ( int i = 0; i < arr.length; i++ ) {
It's a for loop.
We want to iterate over the array and increment each element in the array by 1.
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for ( int i = 0; i < arr.length; i++ ) {
It's a for loop.
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.
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for ( int i = 0; i < arr.length; i++ ) {
It's a for loop.
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.
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for ( int i = 0; i < arr.length; i++ ) {
The loop starts with the iteration variable value as 0 and runs as long as the its value is less than the length of the array length, incrementing it's value by 1 each time because of i++ .
We want to iterate over the array and increment each element in the array by 1.
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