I'm a beginner trying to rewrite the underline function _.invoke.
I'm trying to create the function so that it returns an array containing the results of calling the method on each value in the collection.
_.invoke = function(collection, methodName) {
var result = [];
if (Array.isArray(collection)) {
for (let i = 0; i < collection.length; i++) {
methodName.call(collection[i])
var value = collection[i][methodName]
result.push(value)
}
}
return result
}
I think my problem is with this line:
methodName.call(collection[i]) - Want to call a method on object collection[i], but I want to pass some parameters if they are included in the unit test ).
So far I have tried using the test: typeof(methodName) === "function" and writing a function to test if the method is a function.
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Here you can call with parameters.
_.invoke = function(collection, methodName, ...args) { if (!Array.isArray(collection)) { return []; } const out = []; for(const item of collection){ if(typeof item[methodName] === 'function') out.push(item[methodName].apply(item, args)); } } return out; }There is a method to test all projects:
Is this what you mean?
const myArr = [ { cons:function(args) { return args } }, { cons:function(args) { return args["bla"] } }, ] const _ = {}; _.invoke = (collection, methodName, ...args) => !Array.isArray(collection) ? [] : collection .filter(item => typeof item[methodName] === 'function') .map(item => item[methodName].apply(item, args)); const res = _.invoke(myArr,"cons",{"bla":"hello"}) console.log(res)