name: duk_to_int

proto: |
  duk_int_t duk_to_int(duk_context *ctx, duk_int_t index);

stack: |
  [ ... val! ... ] -> [ ... ToNumber(val)! ... ]

summary: |
  <p>Replace the value at <code>index</code> with an Ecmascript
  <a href="http://www.ecma-international.org/ecma-262/5.1/#sec-9.4">ToInteger()</a>
  coerced value.  Returns an <code>duk_int_t</code> further coerced from the <code>ToInteger()</code>
  result using the algorithm described in
  <code><a href="#duk_get_int">duk_get_int()</a></code> (this second coercion is not
  reflected in the new stack value).  If <code>index</code> is invalid, throws an error.</p>

  <div include="ref-custom-type-coercion.html" />

  <p>If you want the <code>double</code> version of the <code>ToInteger()</code> coerced value,
  use:</p>
  <pre class="c-code">
  double d;

  (void) duk_to_int(ctx, -3);
  d = (double) duk_get_number(ctx, -3);
  </pre>

  <div class="note">
  <code>duk_get_int()</code> int coercion is applied only to the return value, it is not
  reflected on the value stack.  For instance, if value stack contains the string
  <code>"Infinity"</code>, the value on the stack will be coerced to the number
  <code>Infinity</code> and <code>DUK_INT_MAX</code> will be returned from the API call.
  </div>

example: |
  printf("ToInteger() + int coercion: %ld\n", (long) duk_to_int(ctx, -3));
  printf("ToInteger() coercion: %lf\n", (double) duk_get_number(ctx, -3));

tags:
  - stack

introduced: 1.0.0