name: duk_opt_number

proto: |
  duk_double_t duk_opt_number(duk_context *ctx, duk_idx_t idx, duk_double_t def_value);

stack: |
  [ ... val! ... ]

summary: |
  <p>Get the number value at <code>idx</code> without modifying or coercing
  the value.  If the value is <code>undefined</code> or the index is invalid,
  <code>def_value</code> default value is returned.  In other cases
  (<code>null</code> or non-matching type) throws an error.</p>

example: |
  double backoff_multiplier = (double) duk_opt_number(ctx, 2, 1.5);  /* default: 1.5 */

tags:
  - stack

introduced: 2.1.0