What is the problem with: the condition has length > 1 and only the first element will be used?

newbie to r. i have:

  age - function(Age) {
 +     answer-NULL
 +     if(Age15) answer-"under 15"
 +     else if(15=AgeAge=50) answer-"15 to 50"
 +     else answer-"over 50"
 +     answer
 + }
  titanic_3 - titanic %% 
 +     select(Survived, Pclass, Age, Sex) %%
 +     filter(!is.na(Age)) %%
 +     mutate(agecat=age(Age)) Warning message: In if (Age  15) answer - "under 15" else if (15 = Age  Age =  :   the condition has
 length  1 and only the first element will be used
 

if i use one instead of , i get two warnings. i know that one of these is because of the shortcut thing.

how do i write this function so as to get rid of the warning message?

thanks

edit: i tried:

age - function(Age) {
    answer-NULL
    if(Age15) answer-"under 15"
    else if(Age=50) answer-"15 to 50"
    else answer-"over 50"
    answer
}

and got even more warnings:

Warning messages:
1: In if (Age  15) answer - "under 15" else if (Age = 50) answer - "15 to 50" else answer - "over 50" :
  the condition has length  1 and only the first element will be used
2: In if (Age = 50) answer - "15 to 50" else answer - "over 50" :
  the condition has length  1 and only the first element will be used

this one seems to work, but they want us to use cut.

age2 - function(Age) {
    ifelse(Age15,"under 15",ifelse(Age=50,"15 to 50","over 50"))
}