Javascript 常见的循环方式总结

for (let i = 0; i < 5; i++) {
    console.log(`第${i + 1}次循环遍历`)
}

let i = 0;
while (i < 100) {
    i = i + 1;
    console.log(`第${i}次循环遍历`)
}

let a = 3;
let b = 0;

do {
    console.log("打印b的值>>>>>",b);
    b++;
} while (b < a); // 当a小于等于b的时候终止她。

let kj = {
    "a": 1,
    "b": 2,
    "c": 3
}


//使用for-in遍历这个对象
for (let k in kj) {
    console.log(k, kj[k])
}

let arr = [1, 2, 4, 5, 6, 7]
for (let v of arr) {
    console.log(v);
}

const originalArray = [1, 2, 3, 4, 5];
const newArray = originalArray.map((number) => {
  console.log(number)
  return number * 2;
});

console.log(newArray); // Output: [2, 4, 6, 8, 10]

const originalArray = [1, 2, 3, 4, 5];
originalArray.forEach((number) => {
  console.log(number * 2);
});

const originalArray = [1, 2, 3, 4, 5];
const filteredArray = originalArray.filter((number) => {
  // 只返回能被2整除的数 也就是偶数
  return number % 2 === 0;
});

console.log(filteredArray);

function* zip(...arrays) {
    let minLength = Math.min(...arrays.map(arr => arr.length));
    for (let i = 0; i < minLength; i++) {
        yield arrays.map(arr => arr[i]);
    }
}

let aList = [1, 2, 3]
let bList = ["a", "b", "c"]

for (let [a, b] of zip(aList, bList)) {
    console.log(a, b)
}

const numbers = [2, 4, 6, 8, 12];
const hasLargeNumber = numbers.some(function(element) {
  return element > 10;
});

console.log(hasLargeNumber); 

const numbers = [2, 4, 6, 8, 12];
const hasLargeNumber = numbers.every(function(element) {
  return element > 10;
});

console.log(hasLargeNumber);

const numbers = [1, 2, 3, 4, 5];
//accumulator： 表示当前已经累积的值初始值是0 currentValue 表示当前正在被遍历的数组元素。
const sum = numbers.reduce(function(accumulator, currentValue) {
  console.log(accumulator,currentValue)
  return accumulator + currentValue;
}, 0);

console.log(sum)

const numbers = [1, 2, 3, 4, 5];
//accumulator： 表示当前已经累积的值初始值是0 currentValue 表示当前正在被遍历的数组元素。
const sum = numbers.reduceRight(function(accumulator, currentValue) {
  console.log(accumulator,currentValue)
  return accumulator + currentValue;
}, 0);

console.log(sum)