float4() — PostgreSQL JSON function

float4(): convert int2 to float4. PostgreSQL json functions — signature, volatility, version applicability and an illustrative example.

The Sev-1 Admin
The Sev-1 Admin  ·  2 min read

Summary

float4 is a PostgreSQL built-in function in the JSON Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “convert int2 to float4”.

Signature

float4 has 6 documented overloaded forms:

float4(smallint) → real
float4(double precision) → real
float4(integer) → real
float4(bigint) → real
float4(numeric) → real
float4(jsonb) → real

Argument and return types are taken from the pg_proc catalog; internal type names are shown using their readable SQL spellings (for example int4 is shown as integer). (Derived from the catalog — see the linked reference for the canonical documentation.)

Classification

  • Category: JSON Functions
  • Kind: Function
  • Volatility: IMMUTABLE — Marked IMMUTABLE — it always returns the same result for the same arguments and can be used in indexes and other contexts that require immutability.
  • Returns: real

Example

Illustrative form (replace placeholder values with your own data):

SELECT float4(42);

The example above is illustrative and is meant to show calling syntax only; consult the linked PostgreSQL documentation for exact semantics, edge cases and accepted argument combinations.

Version applicability

float4 is present across the surveyed releases (PostgreSQL 15, 16, 17, 18, 19). On older major versions, behaviour may differ in detail — always check the documentation for the version you run.

Related & references

Reference: PostgreSQL documentation — JSON Functions.