#VALID STRING
c <- "single quote ' in between double quotes"
print(c)

d <- 'double quotes " in between single quotes'
print(d)

#invalid strings.
e <- 'mixed quotes"
print(e)

f <- 'single quotes ' inside single quote'
print(f)

#manupulation.

abc <- "hello man"
def <- 'how'
hij <- "are you felling "

print(paste(abc,def,hij))

print(paste(abc,def,hij, sep = "-"))

print(paste(abc,def,hij, sep = "", collapse = ""))