R Intermediate

🚀 Welcome to R Intermediate! Now that you’ve mastered the basics, it’s time to take your R skills to the next level. In this section, you’ll dive into Indexing, Conditional Statements, and Loops—core tools for writing efficient and adaptable code. These concepts are essential for data manipulation, automation, and building reproducible analysis workflows. Let’s build on your foundation and start coding with more precision and control!

Summary Table

Summary of the R Intermediate section.

Concept	Example	Description
One-Based Indexing	vec[1]	First element is at index 1
Negative Indexing	vec[-1]	Excludes the first element
Multi-Level Indexing	lst$name[1], substr(x, 1, 1)	Access nested or character-level elements
Slice Range	vec[2:4]	Inclusive range from index 2 to 4
Slice to End	vec[3:length(vec)]	Elements from index 3 to end
Full Slice	vec[]	All elements
Index Out of Bounds	vec[10]	Returns NA if index exceeds length
Mixed Positive/Negative	vec[c(-1, 2)]	Error if mixing negative and positive indices
if Statement	if (x > 0) { ... }	Runs block if condition is TRUE
else Statement	else { ... }	Runs if if condition is FALSE
else if Statement	else if (x == 0) { ... }	Adds more conditions
Logical Operators	&, |, !	Combine or negate logical conditions
Nested Conditionals	if (...) { if (...) { ... }}	Place one if inside another
for Loop	for (i in 1:5) { ... }	Iterate over values in a vector
Loop over Characters	for (i in seq_len(nchar(str)))	Index through a string
Loop over List	for (name in names(list)) { ... }	Iterate over names and values in a list
while Loop	while (x > 0) { ... }	Continue loop while condition is TRUE
break	if (x == target) break	Exit loop early
next	if (x == skip) next	Skip current iteration
Infinite Loop	while (TRUE) { ... }	Runs forever unless manually stopped