数据类型判断
var toString = Object.prototype.toString;
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基本类型
/**
* Determine if a value is undefined
*
* @param {Object} val The value to test
* @returns {boolean} True if the value is undefined, otherwise false
*/
function isUndefined(val) {
return typeof val === 'undefined';
}
/**
* Determine if a value is a String
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a String, otherwise false
*/
function isString(val) {
return typeof val === 'string';
}
/**
* Determine if a value is a Number
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Number, otherwise false
*/
function isNumber(val) {
return typeof val === 'number';
}
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引用类型
/**
* Determine if a value is a Function
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Function, otherwise false
*/
function isFunction(val) {
return toString.call(val) === '[object Function]';
}
/**
* Determine if a value is an Object
*
* @param {Object} val The value to test
* @returns {boolean} True if value is an Object, otherwise false
*/
function isObject(val) {
return val !== null && typeof val === 'object';
}
/**
* Determine if a value is a plain Object
*
* @param {Object} val The value to test
* @return {boolean} True if value is a plain Object, otherwise false
*/
function isPlainObject(val) {
if (toString.call(val) !== '[object Object]') {
return false;
}
var prototype = Object.getPrototypeOf(val);
return prototype === null || prototype === Object.prototype;
}
/**
* Determine if a value is an Array
*
* @param {Object} val The value to test
* @returns {boolean} True if value is an Array, otherwise false
*/
function isArray(val) {
return toString.call(val) === '[object Array]';
}
/**
* Determine if a value is a Date
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Date, otherwise false
*/
function isDate(val) {
return toString.call(val) === '[object Date]';
}
/**
* Determine if a value is an ArrayBuffer
*
* @param {Object} val The value to test
* @returns {boolean} True if value is an ArrayBuffer, otherwise false
*/
function isArrayBuffer(val) {
return toString.call(val) === '[object ArrayBuffer]';
}
/**
* Determine if a value is a File
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a File, otherwise false
*/
function isFile(val) {
return toString.call(val) === '[object File]';
}
/**
* Determine if a value is a Blob
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Blob, otherwise false
*/
function isBlob(val) {
return toString.call(val) === '[object Blob]';
}
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其他对象类型
/**
* Determine if a value is a Buffer
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Buffer, otherwise false
*/
function isBuffer(val) {
return val !== null && !isUndefined(val) && val.constructor !== null && !isUndefined(val.constructor)
&& typeof val.constructor.isBuffer === 'function' && val.constructor.isBuffer(val);
}
/**
* Determine if a value is a FormData
*
* @param {Object} val The value to test
* @returns {boolean} True if value is an FormData, otherwise false
*/
function isFormData(val) {
return (typeof FormData !== 'undefined') && (val instanceof FormData);
}
/**
* Determine if a value is a view on an ArrayBuffer
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a view on an ArrayBuffer, otherwise false
*/
function isArrayBufferView(val) {
var result;
if ((typeof ArrayBuffer !== 'undefined') && (ArrayBuffer.isView)) {
result = ArrayBuffer.isView(val);
} else {
result = (val) && (val.buffer) && (val.buffer instanceof ArrayBuffer);
}
return result;
}
/**
* Determine if a value is a Stream
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a Stream, otherwise false
*/
function isStream(val) {
return isObject(val) && isFunction(val.pipe);
}
/**
* Determine if a value is a URLSearchParams object
*
* @param {Object} val The value to test
* @returns {boolean} True if value is a URLSearchParams object, otherwise false
*/
function isURLSearchParams(val) {
return typeof URLSearchParams !== 'undefined' && val instanceof URLSearchParams;
}
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