Numbers

Zod provides comprehensive number validation capabilities.

Basic Validation

import { z } from "zod";

// Basic number validation
const numberSchema = z.number();

// Error messages during creation
const age = z.number({
  required_error: "Age is required",
  invalid_type_error: "Age must be a number",
});

Comparison Validation

// Greater than/Less than
z.number().gt(5);  // greater than 5
z.number().gte(5); // greater than or equal to 5 (alias: .min(5))
z.number().lt(5);  // less than 5
z.number().lte(5); // less than or equal to 5 (alias: .max(5))

// Integer validation
z.number().int(); // must be an integer

// Range validation
z.number().min(0).max(100); // between 0 and 100

Special Number Validation

// Positive/Negative
z.number().positive();     // > 0
z.number().nonnegative(); // >= 0
z.number().negative();    // < 0
z.number().nonpositive(); // <= 0

// Multiple validation
z.number().multipleOf(5); // must be divisible by 5 (alias: .step(5))

// Finite validation
z.number().finite();      // must not be Infinity or -Infinity

// Safe number validation
z.number().safe();        // must be between Number.MIN_SAFE_INTEGER and MAX_SAFE_INTEGER

Custom Error Messages

z.number()
  .int({ message: "Please enter an integer" })
  .positive({ message: "Number must be positive" })
  .max(100, { message: "Number must not exceed 100" });

// Combined validation example
const ageSchema = z.number()
  .int({ message: "Age must be an integer" })
  .min(0, { message: "Age cannot be negative" })
  .max(120, { message: "Age cannot exceed 120" });

Type Coercion

// Using coerce for type conversion
const numberSchema = z.coerce.number();

numberSchema.parse("123");     // => 123
numberSchema.parse(true);      // => 1
numberSchema.parse(false);     // => 0
numberSchema.parse("12.3");    // => 12.3

// Combined usage
const positiveInt = z.coerce.number()
  .int({ message: "Must be an integer" })
  .positive({ message: "Must be positive" });

positiveInt.parse("123");  // => 123
positiveInt.parse("-123"); // throws error: Must be positive
positiveInt.parse("12.3"); // throws error: Must be an integer