In R, the break keyword is used to prematurely exit a for loop. When encountered, the break statement immediately terminates the loop and execution continues with the next statement after the loop.

You would prefer to use 'paste0()' over 'paste()' in R when you want to concatenate strings without a separator. The 'paste0()' function is a variation of the 'paste()' function that does not include a separator by default.

In R, an array is created using the array() function. The array() function allows you to specify the values of the array, the dimensions, and other parameters such as dimension names. You can pass a vector of values and specify the dimensions to create the desired array structure.

To calculate the mode of a numeric vector in R, you would use a custom function that counts the frequencies of values and identifies the most frequent value(s) as the mode(s).

The '<-' operator is commonly used in R for assignment, although the '=' operator can also be used. However, '<-' is generally preferred because it makes the code more readable and avoids confusion with the '=' operator used for passing arguments to functions.

A for loop in R iterates over a sequence of values, which can be a vector or a list. The loop variable takes on each value in the sequence for each iteration of the loop.

In R, a function is defined using the function keyword. It is followed by the function name, input parameters, and the function body. The function keyword is used to explicitly indicate the beginning of a function definition in R.

In R, the Unicode escape sequence follows the format uNNNN, where NNNN represents the hexadecimal code point of the Unicode character. For example, u00E9 represents the character é.

All of the mentioned strategies can be used to handle a large data frame that is not memory-efficient. Using the data.table package, splitting the data frame, and removing unnecessary columns are effective ways to optimize memory usage and improve processing efficiency.

To calculate the mode of a factor in R, you could convert it to a numeric vector (using as.numeric()) and then use a custom mode function that is designed to work with numeric vectors.

To generate a multiplication table using nested for loops in R, you can use the following code: for (i in 1:10) { for (j in 1:10) { print(i * j) } }. It iterates over the values 1 to 10 for both i and j, and within each iteration, calculates and prints the product of i and j.

Using R's debugging functions such as traceback(), debug(), browser(), and recover() can help pinpoint where an error occurs. It's also important to review the code for possible syntax errors. If the error is complex, replicating it in a simpler context can sometimes help illuminate the cause.