console.time('time')
console.log('Hello World')
console.timeEnd('time')
// Hello World
// time: 7.991ms

Note: console.time and console.timeEnd() must have same "string" name, which is time here.

It is really handy when you are learning Algorithums and you want to measure the time taken to execute the code.

それを試してみましょう。

let nums = [];
// it's empty array.
for (let i = 0; i < 1000000; i++) {
    // making a loop over 1 million times; and pushing it.
    nums.push(Math.floor(Math.random() * 1000000));
}
// sorting the arrray
nums.sort(function (a, b) { return a - b });

線形探索Algoによる解法

let LinearSearch = function (nums, target) {
    console.time("linear")
    for (let i = 0; i < nums.length; i++) {
        if (nums[i] === target) {
            console.timeEnd("linear")
            return i;
        }
    }
    console.timeEnd("linear")
    return -1;
}
// find million and 1
LinearSearch(nums, 1000001);
console.log(LinearSearch(nums, 1000001));
// linear: 10.044ms
// -1

バイナリ検索の使用例

// Make a function of binary search
let nums = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
let target = 5;


let BinarySearch = function (nums, target) {
    console.time("binary")
    let start = 0;
    let end = nums.length - 1;
    while (start <= end) {
        let mid = Math.floor((start + end) / 2);
        if (nums[mid] === target) {
            console.timeEnd("binary")
            return mid;
        }
        else if (nums[mid] < target) {
            start = mid + 1;
        }
        else {
            end = mid - 1;
        }
    }
    console.timeEnd("binary")
    return -1;
}
console.log(BinarySearch(nums, 1000001))
// binary: 0.129ms
// -1

それはとても便利なので、機能の時間の概念を理解する初心者になる参照してください。

🫂 読書ありがとう。

質問があれば、私に連絡してください。以下のポストに関するコメント

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