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```{index} single: hashsize; Digest::SHA function
```
```{index} single: Digest::SHA::hashsize; Perl function
```

# hashsize

Return the digest length of a `Digest::SHA` object in bits.

For a given algorithm the hashsize is a constant: 160 for SHA-1, 224
for SHA-224, 256 for SHA-256 and SHA-512/256, 384 for SHA-384, 512 for
SHA-512. Divide by 8 to get the byte length of the output from
`digest`.

## Synopsis

```perl
my $bits = $sha->hashsize;
```

## What you get back

An integer, always a multiple of 8.

## Examples

```perl
my $sha = Digest::SHA->new(256);
print $sha->hashsize;         # 256
print $sha->hashsize / 8;     # 32  (bytes per digest)
```

```perl
my $sha = Digest::SHA->new("SHA-512/224");
print $sha->hashsize;         # 224
```

```perl

## Preallocate output buffer for $sha->digest:

my $buf = "\0" x ($sha->hashsize / 8);
```

## Edge cases

- Called on a non-`Digest::SHA` object, returns `undef`.

## Differences from upstream

Fully compatible with upstream `Digest::SHA` {{ upstream.Digest_SHA }}.

## See also

- `algorithm` — the integer algorithm code for this object.
- `digest` — output whose length is `hashsize / 8` bytes.