For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/predicate.md.
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    Predicate

    allPass
    Returns a predicate that checks if a value satisfies ALL predicates.
    anyPass
    Returns a predicate that checks if a value satisfies ANY predicate.
    both
    Returns a predicate that checks if a value satisfies both predicates.
    either
    Returns a predicate that checks if a value satisfies either predicate.
    isArray
    Checks if a value is an array.
    isArrayBuffer
    Checks if a value is an ArrayBuffer instance.
    isBlob
    Checks if a value is a Blob instance.
    isBoolean
    Checks if a value is a boolean type.
    isBrowser
    Checks if the current execution environment is a browser.
    isBuffer
    Checks if a value is a Buffer instance.
    isDate
    Checks if a value is a Date object.
    isEmpty
    Checks if a value is empty.
    isEmptyObject
    Checks if a plain object has no properties ({}).
    isEqual
    Performs a deep comparison to check if two values are equal.
    isEqualWith
    Checks if two values are equal using a custom comparison function.
    isError
    Checks if a value is an Error object.
    isFile
    Checks if a value is a File object.
    isFiniteNumber
    Checks if a value is a finite number.
    isFunction
    Checks if a value is a function.
    isInteger
    Checks if a value is an integer.
    isIterable
    Checks if a value is iterable.
    isJSON
    Checks if a value is a valid JSON string.
    isJSONArray
    Checks if a value is a valid JSON array.
    isJSONObject
    Checks if a value is a valid JSON object.
    isJSONValue
    Checks if a value is a valid JSON value.
    isLength
    Checks if a value is a valid array length.
    isMap
    Checks if a value is a Map.
    isNaN
    Checks if a value is NaN.
    isNil
    Checks if a value is null or undefined.
    isNode
    Checks if the current runtime environment is Node.js.
    isNotEmpty
    Checks if a value is not empty.
    isNotNil
    Checks if a value is neither null nor undefined.
    isNull
    Checks if a value is null.
    isNumber
    Checks if a value is a number type.
    isObject
    Checks if a value is a non-null object.
    isPlainObject
    Checks if a value is a plain object.
    isPrimitive
    Checks if a given value is a JavaScript primitive.
    isPromise
    Checks if a given value is a Promise instance.
    isRegExp
    Checks if a given value is a RegExp instance.
    isSet
    Checks if a given value is a Set instance.
    isString
    Checks if a given value is a string.
    isSymbol
    Checks if a given value is a symbol.
    isTypedArray
    Checks if a given value is a TypedArray instance.
    isUndefined
    Checks if a given value is undefined.
    isWeakMap
    Checks if a given value is a WeakMap instance.
    isWeakSet
    Checks if a given value is a WeakSet instance.