从具有值的JSON对象获取索引 [英] get index from a JSON object with value

问题描述

这是我的json字符串。

This is my json string.

[{
    "name": "placeHolder",
    "section": "right"
}, {
    "name": "Overview",
    "section": "left"
}, {
    "name": "ByFunction",
    "section": "left"
}, {
    "name": "Time",
    "section": "left"
}, {
    "name": "allFit",
    "section": "left"
}, {
    "name": "allbMatches",
    "section": "left"
}, {
    "name": "allOffers",
    "section": "left"
}, {
    "name": "allInterests",
    "section": "left"
}, {
    "name": "allResponses",
    "section": "left"
}, {
    "name": "divChanged",
    "section": "right"
}]

现在，我的值为 allInterests ，我想查找索引（这种情况;它是'7' ）在上面的字符串中的这个对象。我尝试了以下代码;但它总是返回-1。有人可以帮我找出我哪里出错吗？

Now, i have the value allInterests and i want to find out the index (this case; it is '7') of this object in the above string. I tried the following code; but it always returns -1. Can someone help me to findout where i went wrong ?

var q = MY_JSON_STRING
console.log(q.indexOf( 'allInterests' ) );

谢谢和问候，
Tismon Varghese

Thanks and regards, Tismon Varghese

推荐答案

您必须使用 Array.find 或 Array.filter 或 Array.forEach 。

因为你的值是数组，你需要元素的位置，你将拥有迭代它。

Since you value is array and you need position of element, you will have to iterate over it.

var data = [{"name":"placeHolder","section":"right"},{"name":"Overview","section":"left"},{"name":"ByFunction","section":"left"},{"name":"Time","section":"left"},{"name":"allFit","section":"left"},{"name":"allbMatches","section":"left"},{"name":"allOffers","section":"left"},{"name":"allInterests","section":"left"},{"name":"allResponses","section":"left"},{"name":"divChanged","section":"right"}];
var index = -1;
var val = "allInterests"
var filteredObj = data.find(function(item, i){
  if(item.name === val){
    index = i;
    return i;
  }
});

console.log(index, filteredObj);

var data = [{"name":"placeHolder","section":"right"},{"name":"Overview","section":"left"},{"name":"ByFunction","section":"left"},{"name":"Time","section":"left"},{"name":"allFit","section":"left"},{"name":"allbMatches","section":"left"},{"name":"allOffers","section":"left"},{"name":"allInterests","section":"left"},{"name":"allResponses","section":"left"},{"name":"divChanged","section":"right"}];

var val = "allInterests"
var index = data.findIndex(function(item, i){
  return item.name === val
});

console.log(index);

默认 Array.indexOf（）将匹配se archValue到当前元素而不是它的属性。您可以参考 Array.indexOf - polyfill 在MDN上

Default Array.indexOf() will match searchValue to current element and not its properties. You can refer Array.indexOf - polyfill on MDN

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