javascript - 函数中缺少元素

Question

该函数应该创建并显示一个包含数字的数组。缺少一些元素，导致该数组无法显示，因此无法满足“console.log”假设:

function createArray(number) {
    var newArray = [/*10*/];

    for(var counter = 1; counter <= number; counter++) {
        newArray.push(counter);
    }
}

console.log("table with numbers up to 6 = " + createArray(6));
console.log("table with numbers up to 1 = " + createArray(1));
console.log("Testing negatives (should display an empty array) " + createArray(-6));
console.log("Testing 0 (should display an empty array) " + createArray(0));

您能否对此进行分析并提供一些反馈？

Answer 1

函数末尾缺少 return newArray; 。如果没有 return 语句，该函数默认返回 undefined。

function createArray(number) {
    var newArray = [/*10*/];

    for(var counter = 1; counter <= number; counter++) {
        newArray.push(counter);
    }
    return newArray;
}

console.log("table with numbers up to 6 = " + createArray(6));
console.log("table with numbers up to 1 = " + createArray(1));
console.log("Testing negatives (should display an empty array) " + createArray(-6));
console.log("Testing 0 (should display an empty array) " + createArray(0));