﻿ R Programming - Reorder Columns in Data Frame by Column name

# R Programming - Reorder Columns in Data Frame by Column name

## R Programming: Data frame Exercise-18 with Solution

Write a R program to reorder an given data frame by column name.

Sample Solution:

R Programming Code:

``````# Create a data frame named 'exam_data' with columns 'name', 'score', 'attempts', and 'qualify'
exam_data = data.frame(
name = c('Anastasia', 'Dima', 'Katherine', 'James', 'Emily', 'Michael', 'Matthew', 'Laura', 'Kevin', 'Jonas'),
score = c(12.5, 9, 16.5, 12, 9, 20, 14.5, 13.5, 8, 19),
attempts = c(1, 3, 2, 3, 2, 3, 1, 1, 2, 1),
qualify = c('yes', 'no', 'yes', 'no', 'no', 'yes', 'yes', 'no', 'no', 'yes')
)

# Print a message indicating the original data frame
print("Original dataframe:")

# Print the contents of 'exam_data'
print(exam_data)

# Print a message indicating that columns will be reordered
print("Reorder by column name:")

# Reorder columns of 'exam_data' to the specified order
exam_data = exam_data[c("name", "attempts", "score", "qualify")]

# Print the reordered data frame
print(exam_data)
``````

Output:

```[1] "Original dataframe:"
name score attempts qualify
1  Anastasia  12.5        1     yes
2       Dima   9.0        3      no
3  Katherine  16.5        2     yes
4      James  12.0        3      no
5      Emily   9.0        2      no
6    Michael  20.0        3     yes
7    Matthew  14.5        1     yes
8      Laura  13.5        1      no
9      Kevin   8.0        2      no
10     Jonas  19.0        1     yes
[1] "Reorder by column name:"
name attempts score qualify
1  Anastasia        1  12.5     yes
2       Dima        3   9.0      no
3  Katherine        2  16.5     yes
4      James        3  12.0      no
5      Emily        2   9.0      no
6    Michael        3  20.0     yes
7    Matthew        1  14.5     yes
8      Laura        1  13.5      no
9      Kevin        2   8.0      no
10     Jonas        1  19.0     yes
```

Explanation:

• Create Data Frame:
• exam_data = data.frame(...)
• Creates a data frame named exam_data with four columns: name, score, attempts, and qualify.
• Each column is populated with a vector of values, representing student names, scores, number of attempts, and qualification status respectively.
• Print Original Data Frame:
• print("Original dataframe:")
• Prints a message indicating that the original data frame will be displayed.
• print(exam_data)
• Displays the contents of exam_data before any modifications.
• Print Reordering Message:
• print("Reorder by column name:")
• Prints a message indicating that the columns of the data frame will be reordered.
• Reorder Columns:
• exam_data = exam_data[c("name", "attempts", "score", "qualify")]
• Reorders the columns of exam_data according to the specified order: name, attempts, score, qualify.
• Print Reordered Data Frame:
• print(exam_data)
• Displays the contents of the data frame after the columns have been reordered.

R Programming Code Editor:

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