pr_strtod.md - mozsearch

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# PR_strtod

Converts the prefix of a decimal string to the nearest double-precision

floating point number.

## Syntax

```{code}

#include <prdtoa.h>

PRFloat64 PR_strtod(const char *s00, char **se);

```

### Parameters

The function has these parameters:

`s00`

: The input string to be scanned.

`se`

: A pointer that, if not `NULL`, will be assigned the address of the

  last character scanned in the input string.

### Returns

The result of the conversion is a `PRFloat64` value equivalent to the

input string. If the parameter `se` is not `NULL` the location it

references is also set.

## Description

{ref}`PR_strtod` converts the prefix of the input decimal string pointed to

by `s00` to a nearest double-precision floating point number. Ties are

broken by the IEEE round-even rule. The string is scanned up to the

first unrecognized character. If the value of `se` is not

(`char **`) `NULL`, {ref}`PR_strtod` stores a pointer to the character

terminating the scan in `*se`. If the answer would overflow, a

properly signed `HUGE_VAL` (infinity) is returned. If the answer would

underflow, a properly signed 0 is returned. In both cases,

`PR_GetError()` returns the error code `PR_RANGE_ERROR`. If no

number can be formed, `se` is set to `s00`, and 0 is returned.