Substring
A substring is a smaller sequence of characters that appears within a larger character string.
To check if a character string contains a specific substring, follow these steps:
- Define the main character string.
- Define the substring you want to check for.
- Use the if-else statement to check if the substring is present in the main string.
- Execute different code blocks based on the presence or absence of the substring.
Let’s consider a few examples to illustrate how to use the if-else statement in R to check for a specific substring.
Example 1: Checking if a string is present in the string
R
# Step 1: Define the main character string main_string <- "I have an apple and a banana." # Step 2: Define the substring to check for substring_to_check <- "apple" # Step 3: Use the if-else statement to check if the substring is present if ( grepl (substring_to_check, main_string)) { # Step 4a: If the substring is present, execute this block of code print ( "The string contains 'apple'." ) } else { # Step 4b: If the substring is not present, execute this block of code print ( "The string does not contain 'apple'." ) } |
Output:
[1] "The string contains 'apple'."
Example 2: Checking if “mango” is present in the string
R
# Step 1: Define the main character string main_string <- "We are enjoying delicious fruits." # Step 2: Define the substring to check for substring_to_check <- "mango" # Step 3: Use the if-else statement to check if the substring is present if ( grepl (substring_to_check, main_string)) { # Step 4a: If the substring is present, execute this block of code print ( "The string contains 'mango'." ) } else { # Step 4b: If the substring is not present, execute this block of code print ( "The string does not contain 'mango'." ) } |
Output:
[1] "The string does not contain 'mango'."
if-else to check if a character string contains a specific substring.
In R Programming Language, we can use the if-else statement to check if a character string contains a specific substring. The if-else statement allows us to execute different code blocks based on a certain condition, in this case, whether the substring is present in the given string.