为什么我的高阶函数返回true和false?

您正在推送条件的布尔表达式结果,而是将其用作推送所需单词的条件,如下所示

const wordArray = ["mine", "script", "function", "array", "javascript", "python", "coding", "html", "css", "bye"];
//myFilterFunction(HOF) takes an array (arr) and hypothetical function (fn) as arguments//
let myFilterFunction = (arr) => (fn) => {
    const newArray = [];
    for (let i = 0; i < arr.length; i++) {
        if (fn(arr[i])) {
            newArray.push(arr[i]);   
        }
    }
    return newArray; //return a array
};
//myFilterFunction is used with an anonymous function to return whether each word is 6 or more   letters//
const printArray = myFilterFunction(wordArray)((word) => word.length >= 6);
//Output the result to the console//
console.log("this array only contains words that are 6 letters or more: " + printArray);

您将作为参数传递的函数的结果附加到数组中,而不是传递数组的元素

const wordArray = ["mine", "script", "function", "array", "javascript", "python", "coding", "html", "css", "bye"];
//myFilterFunction(HOF) takes an array (arr) and hypothetical function (fn) as arguments
let myFilterFunction = (arr) => (fn) => {
    const newArray = [];
    for (let i = 0; i < arr.length; i++) {
 
      fn(arr[i]) && newArray.push(arr[i]);
//if the condition is true we are adding the element to newArray 

    }
    return newArray; //return a array
};
//myFilterFunction is used with an anonymous function to return whether each word is 6 or more   letters
const printArray = myFilterFunction(wordArray)((word) => word.length >= 6);
//Output the result to the console
console.log("this array only contains words that are 6 letters or more: " + printArray);