Prepend(expr, item)
returns
exprwithitemprepended to its leaves.
Prepend is similar to Append, but adds item to the beginning of expr:
>> Prepend({2, 3, 4}, 1)
{1,2,3,4}
Prepend works on expressions with heads other than 'List':
>> Prepend(f(b, c), a)
f(a,b,c)
Unlike Join, Prepend does not flatten lists in item:
>> Prepend({c, d}, {a, b})
{{a,b},c,d}
Nonatomic expression expected.
>> Prepend(a, b)
Prepend(a,b)
- ✅ - full supported