#     
## What are strings?
**Strings** are a collection of various characters in the R language. These characters are enclosed in single or double quotation marks. Strings can also contain numbers, special characters, or spaces.

We must consider some rules when we construct strings in R:
* Strings with single quotes can contain double-quoted strings and vice versa.
* Double quoted strings cannot contain another double-quoted string.
* Single quoted strings cannot contain another single-quoted string.
* There should be a proper ending and closing for both single and double quotes when constructing strings.

#      
##    
### Example 1
This example demonstrates the rules mentioned above. 



# Properties of String Data Structure in R

str1 <- 'valid string 1'
print(str1)

str2 <- "another valid string"
print(str2)

str3 <- " we can also ' in double quotes "
print(str3)

str4 <- ' example of "valid" strings '
print(str4)


Now, let’s discuss an example of some strings that are not allowed.
#     
##    
### Example 2
A single quote is not allowed in line 4. A double quote within a double quote also produces `Error: unexpected` in line 7.

i1 <- 'not allowed" 
print(i1)

i2 <- 'invalid' string'
print(i2)

i3 <- "it is also" not allowed"
print(i3)


#     
## What is `stringr`?
**`Stringr`** is a package in the R language that is used to perform fast manipulations on strings. `Stringr` contains all the relevant functions to perform string manipulation. Basically, strings are the combinations of various characters, and `stringr` is a package for performing manipulations on these character sequences.

`Stringr` package examples:
Every function in this package will start with `str_`.


#    
##     
### String length
You can get the size of a string or list of strings with the `str_length()` method. This method is equivalent to `nchar()`, which also returns the string's length after the R.3.3.0 update.

---
```R
str_length("abc")
str_length(c("strings", "length"))
```
---

### Combining strings
`str_c()` helps to combine multiple strings; `str_c()` takes a vector of strings and collapses characters, i.e., comma. It returns the condensed string.

---
```R
str_c(x, collapse = ", ")
str_c("what", "are", "strings?")
```
---

### Subsetting strings
You can retrieve the part of strings through this function. We have to initialize the start and end when using this function.

---
```R
a <- c("Black", "White", "Green")
str_sub(a,1,3)
```
---


What is the difference between string and stringr in R?

Strings in R are enclosed character collections. Stringr is a package for string manipulations using functions like str_length(), str_c(), and str_sub().

What is the difference between string and stringr in R?

What are strings?

Example 1

Example 2

What is stringr?

String length

Combining strings

Subsetting strings

What is `stringr`?