假设我有一个包含四个对象的数组:
var jsObjects = [
{a: 1, b: 2},
{a: 3, b: 4},
{a: 5, b: 6},
{a: 7, b: 8}
];
是否有一种方法，我可以通过属性b的值获得第三个对象({a: 5, b: 6})例如，没有a for…在循环?
当前回答
使用find和bind将特定的键值传递给回调函数。
function byValue(o) {
return o.a === this.a && o.b === this.b;
};
var result = jsObjects.find(byValue.bind({ a: 5, b: 6 }));
其他回答
你可以像下面这样使用箭头函数:
var demoArray = [
{name: 'apples', quantity: 2},
{name: 'bananas', quantity: 0},
{name: 'cherries', quantity: 5}
];
var result = demoArray.filter( obj => obj.name === 'apples')[0];
console.log(result);
// {name: 'apples', quantity: 2}
使用find和bind将特定的键值传递给回调函数。
function byValue(o) {
return o.a === this.a && o.b === this.b;
};
var result = jsObjects.find(byValue.bind({ a: 5, b: 6 }));
对象的过滤器数组，属性与值匹配，返回数组:
var result = jsObjects.filter(obj => {
return obj.b === 6
})
请参阅Array.prototype.filter()上的MDN文档
const jsObjects = [ {a: 1, b: 2}， {a: 3, b: 4}， {a: 5, b: 6}， {a: 7, b: 8} ］ let result = jsObjects。过滤器(obj => { 返回obj。B === 6 }) console.log(结果)
找到数组中第一个元素/对象的值，否则返回undefined。
var result = jsObjects.find(obj => {
return obj.b === 6
})
请参阅Array.prototype.find()上的MDN文档
const jsObjects = [ {a: 1, b: 2}， {a: 3, b: 4}， {a: 5, b: 6}， {a: 7, b: 8} ］ let result = jsObjects。Find (obj => { 返回obj。B === 6 }) console.log(结果)
通过特定的属性值从对象数组中获取第一个对象:
function getObjectFromObjectsArrayByPropertyValue(objectsArray, propertyName, propertyValue) { return objectsArray.find(function (objectsArrayElement) { return objectsArrayElement[propertyName] == propertyValue; }); } function findObject () { var arrayOfObjectsString = document.getElementById("arrayOfObjects").value, arrayOfObjects, propertyName = document.getElementById("propertyName").value, propertyValue = document.getElementById("propertyValue").value, preview = document.getElementById("preview"), searchingObject; arrayOfObjects = JSON.parse(arrayOfObjectsString); console.debug(arrayOfObjects); if(arrayOfObjects && propertyName && propertyValue) { searchingObject = getObjectFromObjectsArrayByPropertyValue(arrayOfObjects, propertyName, propertyValue); if(searchingObject) { preview.innerHTML = JSON.stringify(searchingObject, false, 2); } else { preview.innerHTML = "there is no object with property " + propertyName + " = " + propertyValue + " in your array of objects"; } } } pre { padding: 5px; border-radius: 4px; background: #f3f2f2; } textarea, button { width: 100% } <fieldset> <legend>Input Data:</legend> <label>Put here your array of objects</label> <textarea rows="7" id="arrayOfObjects"> [ {"a": 1, "b": 2}, {"a": 3, "b": 4}, {"a": 5, "b": 6}, {"a": 7, "b": 8, "c": 157} ] </textarea> <hr> <label>property name: </label> <input type="text" id="propertyName" value="b"/> <label>property value: </label> <input type="text" id="propertyValue" value=6 /> </fieldset> <hr> <button onclick="findObject()">find object in array!</button> <hr> <fieldset> <legend>Searching Result:</legend> <pre id="preview">click find</pre> </fieldset>
让这个答案的最佳/最快部分更具可重用性和清晰性:
function getElByPropVal(myArray, prop, val){
for (var i = 0, length = myArray.length; i < length; i++) {
if (myArray[i][prop] == val){
return myArray[i];
}
}
}
