Question

你好，我有一个包含大范围值的数组，我需要从该数组中获取值范围并做XMLHttpRequest我已经做过的例子：

var servoangle = [1.2,1.3,1.4,1.5,1.6,1.7,1.8,1.9,2,2.1,2.2....];
var params = "motor1=" + servoangle[0] + "&motor2=" + servoangle[2] + "&motor4=" + servoangle[3] + "&motor5=" + servoangle[4] + "&motor6=" + servoangle[5] + "&motor7=" + servoangle[6] + "&";
var url = "/finaltest2please.php"
var http = new XMLHttpRequest();

http.open('POST', url, true);

//Send the proper header information along with the request
http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');

http.onreadystatechange = function() {//Call a function when the state changes.
    if(http.readyState == 4 && http.status == 200) {
        console.log(http.responseText);
    }
}
http.send(params);

我想要实现的是如何获取前5个值，然后获取接下来的5个值，依此类推

Answer 1

您可以使用此数组的.slice方法

const arr = [1,2,3,4,5,6,7,8,9,10,11,12];
console.log(arr.slice(0,5)) // first 5 values
console.log(arr.slice(5,10)) // next 5
console.log(arr[10]) // so one 11-th

Answer 2

尝试一下：

const arr = [0,1,2,3,4,5,6,7,8,9];

const send = (from, to) => {
    let url = '/page.php?';
    let formData = new FormData();
    for (let i=from; i<to; i++) {
        formData.append(`motor${i}`, arr[i])
    }
    fetch(url, {
        method: 'post',
        headers: { 'Content-type': 'application/x-www-form-urlencoded'}
        body: formData
    });
}

for (let i=0; i<arr.length-5; i+=5) { send(i, i+5); }

从具有特定范围的数组中获取值-Javascript

2 个答案: