title: Julia: Convert numeric string to float or int
body: <p>I am trying to write numeric data pulled from a database into a <code>Float64[]</code>. The original data is in <code>::ASCIIString</code> format, so trying to push it to the array gives the following error:</p>
  
  <pre><code>julia&gt; push!(a, "1")
  ERROR: MethodError: `convert` has no method matching convert(::Type{Float64}, ::ASCIIString)
  This may have arisen from a call to the constructor Float64(...),
  since type constructors fall back to convert methods.
  Closest candidates are:
    call{T}(::Type{T}, ::Any)
    convert(::Type{Float64}, ::Int8)
    convert(::Type{Float64}, ::Int16)
    ...
   in push! at array.jl:432
  </code></pre>
  
  <p>Attempting to convert the data directly unsurprisingly throws the same error:</p>
  
  <pre><code>julia&gt; convert(Float64, "1")
  ERROR: MethodError: `convert` has no method matching convert(::Type{Float64}, ::ASCIIString)
  This may have arisen from a call to the constructor Float64(...),
  since type constructors fall back to convert methods.
  Closest candidates are:
    call{T}(::Type{T}, ::Any)
    convert(::Type{Float64}, ::Int8)
    convert(::Type{Float64}, ::Int16)
    ...
  </code></pre>
  
  <p>Given that I know the data is numeric, is there a way I can convert it before pushing?</p>
  
  <p>p.s. I am using version 0.4.0</p>