node.js 节点js检查var是否是一个函数
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Node js check if a var is a function
提问by Rolando Corratge Nieves
Possible Duplicate:
How can I check if a javascript variable is function type?
How i check if a variable is a function
for Array exist Array.isArray()but Function.isFunctiondos'nt exist
我如何检查变量是否是 Array 的函数Array.isArray()但Function.isFunction不存在
回答by paul
if (typeof variable === 'function') {
// do something
}
回答by Manu Letroll
You can use the instanceofoperator.
您可以使用instanceof运算符。
var fn = function() {};
var result = fn instanceof Function; // result will be true
It also respects prototypal inheritance.
它还尊重原型继承。
回答by BadCanyon
Underscore.js is a library that has a lot of useful helpers, like the one you're looking for.
Underscore.js 是一个库，它有很多有用的助手，就像你正在寻找的那样。
_ = require('underscore');
var aFunction = function() { };
var notFunction = 'Not a function';
_.isFunction(aFunction); // true
_.isFunction(notFunction); // false
回答by orustam
var fn = function() {},
toString = Object.prototype.toString;
first way:
if( toString.call( function(){} ) === '[object Function]' ) {
//if is Function do something...
}
second way:
if( fn.constructor.name = 'Function' ) {
//if is Function do something...
}
Hope it helps cheers:)!
希望它有助于欢呼:)！
