# Embedding Julia in C -- error regarding jl\_array\_ptr\_1d\_push

**URL:** <https://discourse.julialang.org/t/embedding-julia-in-c-error-regarding-jl-array-ptr-1d-push/11315>\
**Category:** General Usage\
**Created:** [June 1, 2018, 1:07am UTC](https://discourse.julialang.org/t/embedding-julia-in-c-error-regarding-jl-array-ptr-1d-push/11315 "2018-06-01T01:07:57Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![jinliangwei](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jinliangwei/32/1929_2.png) [@jinliangwei](https://discourse.julialang.org/u/jinliangwei)\
**Post date:** [June 1, 2018, 1:07am UTC](https://discourse.julialang.org/t/embedding-julia-in-c-error-regarding-jl-array-ptr-1d-push/11315/1 "2018-06-01T01:07:57Z")

</div>

```julia
#include <julia.h>

int main(int argc, char* argv[]) {
  jl_init();
  jl_value_t* array_type_jl = nullptr;
  jl_value_t* array_jl = nullptr;
  jl_value_t* value_jl = nullptr;
  JL_GC_PUSH3(&array_type_jl, &array_jl, &value_jl);

  array_type_jl = jl_apply_array_type(
     reinterpret_cast<jl_value_t*>(jl_float64_type), 1);

 array_jl = reinterpret_cast<jl_value_t*>(jl_alloc_array_1d(array_type_jl, 0));
 value_jl = jl_box_float64(64.0);
 jl_array_ptr_1d_push(reinterpret_cast<jl_array_t*>(array_jl), value_jl);
 jl_function_t* print_func = jl_get_function(jl_base_module, "println");
 jl_call1(print_func, array_jl);
 JL_GC_POP();
 jl_atexit_hook(0);
}

```

For the code above, I was expecting `array_jl` to contain a `Float64` number `64.0` but it is actually `6.9438e-310`. What did I do wrong?

---

<div class="post-metadata">

**Author:** ![barche](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/barche/32/79_2.png) [@barche](https://discourse.julialang.org/u/barche)\
**Post date:** [June 1, 2018, 3:18pm UTC](https://discourse.julialang.org/t/embedding-julia-in-c-error-regarding-jl-array-ptr-1d-push/11315/2 "2018-06-01T15:18:26Z")

</div>

I’m not sure `jl_array_ptr_1d_push` is applicable here, since this seems to be for an array with element type `Any`. I use this sequence in my code:

```julia
const size_t pos = jl_array_len(m_array);
jl_array_grow_end(m_array, 1);
jl_arrayset(m_array, box(val), pos);

```

Also, note that you can wrap a C array of doubles using `jl_ptr_to_array`, which would be a lot simpler in this case.