js ajax 获得参数

// 假设URL是 "http://example.com/?param1=value1&param2=value2"
const urlParams = new URLSearchParams(window.location.search);
const param1 = urlParams.get('param1'); // "value1"
const param2 = urlParams.get('param2'); // "value2"

var xhr = new XMLHttpRequest();
xhr.open("POST", 'http://example.com/api', true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.onreadystatechange = function() {
    if (xhr.readyState === 4 && xhr.status === 200) {
        var response = JSON.parse(xhr.responseText);
        console.log(response.param); // 假设服务器返回 {"param": "value"}
    }
};
xhr.send("param=value");

fetch('http://example.com/api', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json'
    },
    body: JSON.stringify({ param: 'value' })
})
.then(response => response.json())
.then(data => console.log(data.param)); // "value"

fetch('http://example.com/api')
.then(response => response.json())
.then(data => {
    console.log(data.param); // 假设服务器返回 {"param": "value"}
});