String slicing and indexing in Ruby - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of negative index slicing

What is the output of this Ruby code?

Ruby

str = "programming"
puts str[-4, 3]

A "amm"

B "min"

C "mmi"

D "ing"

💡 Hint

Remember that negative index counts from the end, and the second number is length.

str[-4, 3] starts 4 characters from the end ('m') and takes 3 characters: 'm', 'm', 'i'.

❓ Predict Output

intermediate

Output of range slicing

What will this Ruby code print?

Ruby

text = "hello world"
puts text[2..5]

A "llo "

B "llo w"

C "lo w"

D "ello"

💡 Hint

Range includes both start and end indices.

text[2..5] extracts characters at indices 2,3,4,5: 'l','l','o',' '.

🔧 Debug

advanced

Identify the error in slicing

What error does this Ruby code raise?

Ruby

word = "example"
puts word[3, -2]

A nil output (no error)

B ArgumentError

C TypeError

D IndexError

💡 Hint

Negative length in slice returns nil instead of error.

In Ruby, a negative length in slice returns nil, no error is raised.

❓ Predict Output

advanced

Output of slice with range and negative indices

What is the output of this Ruby code?

Ruby

s = "abcdefg"
puts s[-5..-3]

A "cdef"

B "cde"

C "def"

D "bcd"

💡 Hint

Negative indices count from the end, inclusive range.

s[-5..-3] means indices 2 to 4: 'c','d','e'.

🧠 Conceptual

expert

Number of characters extracted by slice

How many characters does this Ruby slice extract?

Ruby

str = "university"
result = str[1, 4]

A 6

B 5

C 3

D 4

💡 Hint

The second argument is the length of the slice.

str[1,4] extracts 4 characters starting at index 1.