R Booleans / Logical Values

🔢 R Booleans / Logical Values

In R, Boolean values (also called logical values) represent TRUE or FALSE.
They are the foundation of conditions, filtering, decision-making, and data analysis.

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1️⃣ What are Logical Values in R?

R has two logical constants:

📌 They are case-sensitive (TRUE ✔, true ❌).

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2️⃣ Creating Logical Values

Logical values are created using comparison operators.

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3️⃣ Logical Variables

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4️⃣ Logical Vectors ⭐

R supports vectorized logical operations.

📌 Very important for data filtering.

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5️⃣ Logical Operators 🔗

Element-wise Logical Operators

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Short-circuit Logical Operators ⭐

📌 Used mainly in if conditions.

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6️⃣ Logical Values in if Statement ⭐

⚠️ if requires a single TRUE/FALSE, not a vector.

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7️⃣ Logical Values with which() ⭐

✔ Returns positions of TRUE values.

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8️⃣ Logical Values with any() and all() ⭐

any()

Returns TRUE if any value is TRUE.

all()

Returns TRUE if all values are TRUE.

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9️⃣ Handling NA in Logical Values ⚠️

📌 Use na.rm = TRUE to ignore NA.

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🔟 Logical Values vs Numeric Values

✔ Useful in calculations.

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1️⃣1️⃣ Common Mistakes ❌

❌ Using true instead of TRUE
❌ Using vector in if condition
❌ Confusing & and &&
❌ Ignoring NA values

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📌 Interview Questions & MCQs (Very Important)

Q1. What are logical values in R?

A) 1 and 0
B) TRUE and FALSE
C) Yes and No
D) T and F

✅ Answer: B

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Q2. Are logical values case-sensitive?

A) Yes
B) No

✅ Answer: A

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Q3. Difference between & and &&?

A) Both same
B) && works element-wise
C) & works element-wise
D) No difference

✅ Answer: C

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Q4. What does any() do?

A) Checks all TRUE
B) Checks any TRUE
C) Counts TRUE
D) Filters data

✅ Answer: B

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Q5. Output of as.numeric(TRUE)?

A) 0
B) 1
C) TRUE
D) Error

✅ Answer: B

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🔥 Real-Life Use Cases

✔ Filtering datasets
✔ Conditional logic
✔ Decision making
✔ Data validation
✔ Statistical rules

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✅ Summary

• R has TRUE and FALSE

• Logical values are created via comparisons

• R supports vectorized logical operations

• & vs && is crucial

• Handle NA carefully

• Core concept for R programming, exams & data science