# Merge to number

**URL:** <https://discourse.julialang.org/t/merge-to-number/44583>\
**Category:** New to Julia\
**Created:** [August 8, 2020, 8:15pm UTC](https://discourse.julialang.org/t/merge-to-number/44583 "2020-08-08T20:15:25Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Fuad\_Sami](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fuad_sami/32/16900_2.png) [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Post date:** [August 8, 2020, 8:15pm UTC](https://discourse.julialang.org/t/merge-to-number/44583/1 "2020-08-08T20:15:25Z")

</div>

hi all  
i have two arrays a and b  
find the maximum between a[i] and b[i] and return it  
if i have `a = [1,5,9,2] and b =[3,3,7,8,6,4]`  
the output will be  
`res = [3,5,9,8,6,4]`  
it is easy i know but i don’t know why my code not 100% working.

it is not issue of julia forgive me but if some one can fix it i appreciate that

thanks

this is my code…

```julia
function MaxPair(a,b)
   
    if length(a) >= length(b)
        c = length(a)
        sh = length(b)
    else  
        c = length(b)
        sh = length(a)
    end
    println(c , sh)
    res = Array{Int64}(undef,c)
    i=1
    while i<=sh
        if a[i] >= b[i]
            res[i] = a[i]
            i+=1
        else
            res[i] = b[i]
            i +=1
        end
    end
    if length(a) >= length(b)
        while sh<=length(a)
            res[sh] = a[sh]
            sh+=1
        end
    end
    if length(b) >= length(a) 
        while sh <= length(b)
            res[sh] = b[sh]
            sh+=1
        end
    end
    return res
end
a = [1,5,880,9999]
b = [3,2,9,99999]
println(MaxPair(a,b))

```

---

<div class="post-metadata">

**Author:** ![anon37204545](https://avatars.discourse-cdn.com/v4/letter/a/439d5e/32.png) [@anon37204545](https://discourse.julialang.org/u/anon37204545)\
**Post date:** [August 8, 2020, 8:20pm UTC](https://discourse.julialang.org/t/merge-to-number/44583/2 "2020-08-08T20:20:26Z")

</div>

You have to redefine `a` to be of the same size as `b`.

```julia
julia> a = [1,5,9,2,0,0]

```

Then it’s as easy as this:

```julia
julia> max.(b, a)
6-element Array{Int64,1}:
 3
 5
 9
 8
 6
 4

```

---

<div class="post-metadata">

**Author:** ![Fuad\_Sami](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fuad_sami/32/16900_2.png) [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Post date:** [August 8, 2020, 8:23pm UTC](https://discourse.julialang.org/t/merge-to-number/44583/3 "2020-08-08T20:23:57Z")

</div>

and if i don’t know the length in the first place ?

can you write it with the familiar way not with max.

---

<div class="post-metadata">

**Author:** ![tomerarnon](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomerarnon/32/3170_2.png) [@tomerarnon](https://discourse.julialang.org/u/tomerarnon)\
**Post date:** [August 8, 2020, 8:43pm UTC](https://discourse.julialang.org/t/merge-to-number/44583/4 "2020-08-08T20:43:25Z")

</div>

Here’s an idea to handle different length arrays the way you describe your output:

```julia
function max_pair(a, b)
    na, nb = length(a), length(b)
    na == nb && return max.(a, b)

    # make sure a is the longer one
    if nb > na
        a, b = b, a
        na, nb = nb, na
    end
    # compare the comparable
    maxes = max.(a[1:nb], b)
    # append the rest
    append!(maxes, a[nb+1:end])
    return maxes
end

```

---

<div class="post-metadata">

**Author:** ![Fuad\_Sami](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fuad_sami/32/16900_2.png) [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Post date:** [August 8, 2020, 9:51pm UTC](https://discourse.julialang.org/t/merge-to-number/44583/5 "2020-08-08T21:51:20Z")

</div>

that’s help  
thanks  
here is the final code, i want it with out the max.

```julia
function MaxPair(a,b)
    na, nb = length(a), length(b)
    # make sure a is the longer one
    if nb > na
        a, b = b, a
        na, nb = nb, na
    end
    res = Array{Int64}(undef,na)
    i=1
    while i<=nb
        if a[i] >= b[i]
            res[i] = a[i]
            i+=1
        else
            res[i] = b[i]
            i +=1
        end
    end
        while nb+1<=length(a)
            res[nb+1] = a[nb+1]
            nb+=1
        end
    return res
end
a = [1,5,880,99,3254,3245,3254,345,3245,324599]
b = [3,2,9,9999,2345,324,3,4,34,3254,2345,23244,4,234,2435,9]
println(MaxPair(a,b))

```