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How do you convert a numeric value to a string in R? a) as.numeric() b) as.character() c) numToString() d) str_numeric() Answer: b) as.character() Explanation: The as.character() function is used to convert a numeric value into a string in R. Reference: R Programming – String MCQ Questions and Answers

Which function in R converts a string to a raw vector? a) rawToChar() b) charToRaw() c) str_raw() d) raw_vector() Answer: b) charToRaw() Explanation: The charToRaw() function converts a character string into a raw vector in R. Reference: R Programming – String MCQ Questions and Answers

How do you reverse the characters in a string in R? a) reverse() b) rev_string() c) str_reverse() d) rev() Answer: c) str_reverse() Explanation: The str_reverse() function reverses the order of characters in a string. Reference: R Programming – String MCQ Questions and Answers

What is the output of the expression nchar("Data")? a) 4 b) 3 c) 5 d) 2 Answer: a) 4 Explanation: The nchar() function returns the length of the string, which is 4 in this case. Reference: R Programming – String MCQ Questions and Answers

How do you detect if a string starts with a specific substring in R? a) str_starts() b) startsWith() c) start_string() d) begins() Answer: b) startsWith() Explanation: The startsWith() function checks if a string starts with a given substring in R. Reference: R Programming – String MCQ Questions and Answers

What is the result of the expression substr("R Language", 3, 5)? a) “Lang” b) “Lan” c) “Language” d) “R L” Answer: b) “Lan” Explanation: The substr() function extracts characters from the 3rd to the 5th position, which gives “Lan”. Reference: R Programming – String MCQ Questions and Answers

Which function in R is used to search for a pattern in a string? a) match() b) search() c) grep() d) pattern() Answer: c) grep() Explanation: The grep() function is used to search for patterns in strings in R, returning matching elements. Reference: R Programming – String MCQ Questions and Answers

How do you convert a string to lowercase in R? a) tolower() b) str_lower() c) lowercase() d) toLowerCase() Answer: a) tolower() Explanation: The tolower() function converts all characters of a string to lowercase in R. Reference: R Programming – String MCQ Questions and Answers

How do you trim leading and trailing whitespaces in R? a) strip() b) trim() c) trimws() d) stripws() Answer: c) trimws() Explanation: The trimws() function removes leading and trailing whitespaces from a string in R. Reference: R Programming – String MCQ Questions and Answers

Which function is used to split a string in R? a) split() b) strsplit() c) divide() d) slice() Answer: b) strsplit() Explanation: The strsplit() function splits a string into substrings based on a specified delimiter. Reference: R Programming – String MCQ Questions and Answers

How do you replace a part of a string in R? a) replace() b) gsub() c) str_replace() d) substitute() Answer: b) gsub() Explanation: The gsub() function is used to replace all occurrences of a pattern in a string in R. Reference: R Programming – String MCQ Questions and Answers

How do you find the length of a string in R? a) strlen() b) length() c) nchar() d) str_len() Answer: c) nchar() Explanation: The nchar() function in R returns the number of characters in a string. Reference: R Programming – String MCQ Questions and Answers

Which function is used to extract a substring in R? a) substr() b) str_sub() c) sub() d) substring() Answer: a) substr() Explanation: The substr() function is used to extract a substring from a string, based on starting and ending positions. Reference: R Programming – String MCQ Questions and Answers

How do you convert a string to uppercase in R? a) toupper() b) toUpperCase() c) upper() d) str_upper() Answer: a) toupper() Explanation: The toupper() function converts all characters of a string to uppercase in R. Reference: R Programming – String MCQ Questions and Answers

Which function is used to concatenate strings in R? a) concat() b) paste() c) join() d) merge() Answer: b) paste() Explanation: The paste() function in R is used to concatenate two or more strings together. Reference: R Programming – String MCQ Questions and Answers

What is the maximum length of a variable name in R? a) 256 characters b) 64 characters c) No specific limit d) 128 characters Answer: c) No specific limit Explanation: R does not impose a specific limit on the length of variable names, but they must be syntactically valid.

How can you check if a variable is numeric in R? a) is.character() b) is.logical() c) is.numeric() d) is.double() Answer: c) is.numeric() Explanation: The is.numeric() function returns TRUE if the variable is numeric, otherwise FALSE.

How do you convert a numeric variable to an integer in R? a) as.numeric() b) as.integer() c) convert() d) as.type() Answer: b) as.integer() Explanation: The as.integer() function is used to convert numeric variables to integers in R.

Which of the following is NOT a valid data type in R? a) character b) string c) numeric d) logical Answer: b) string Explanation: In R, character is used instead of string for text data. Therefore, string is not a valid data type in R.

How can you remove a variable from the workspace in R? a) delete() b) remove() c) rm() d) clear() Answer: c) rm() Explanation: The rm() function in R is used to remove variables from the workspace or environment.

What is the default data type of a variable in R when a number is assigned to it? a) character b) integer c) numeric d) logical Answer: c) numeric Explanation: When a number is assigned to a variable, R treats it as numeric by default unless explicitly defined as an integer.

Which function in R is used to list all variables in the current environment? a) ls() b) list() c) showvars() d) vars() Answer: a) ls() Explanation: The ls() function lists all the variables defined in the current workspace or environment in R.

What function is used to check the type of a variable in R? a) class() b) typeof() c) checktype() d) vartype() Answer: a) class() Explanation: The class() function returns the class of the variable in R, helping you identify its type.

Which of the following is a valid variable name in R? a) 1var b) _variable c) variable_1 d) var-iable Answer: c) variable_1 Explanation: Variable names in R must begin with a letter or a period, followed by letters, digits, or underscores. variable_1 is the only valid option.

Which operator is used to assign a value to a variable in R? a) == b) = c) -> d) <- Answer: d) <- Explanation: The <- operator is commonly used in R to assign a value to a variable. While = can also be used, <- is preferred.