最新消息:雨落星辰是一个专注网站SEO优化、网站SEO诊断、搜索引擎研究、网络营销推广、网站策划运营及站长类的自媒体原创博客

javascript - array length with key-value, js - Stack Overflow

programmeradmin4浏览0评论

I wrote this piece of code, that should parse the given paramUnparsed (which should be an array in the form: [key1=val1, key2=val2, .., keyn=valn]).

function parseParams(paramUnparsed){
var params = [];
for ( var j = 0; j < paramUnparsed.length; j++) {
    if (paramUnparsed[j].split('=').length < 2) {
        // error ! bad input structure, ignoring params -

        params = undefined;
        break; // we don't have to return error, depending
                // on the function called and given params.

    }
    //else {
        var key = paramUnparsed[j].split('=')[0];
        var value = paramUnparsed[j].split('=')[1];
        params[key] = value;
    //}
}

console.log("In parseParams, params are: "+ concatObject(params));//DEBUG 1
console.log("In parseParams, params length is: "+ params.length);//DEBUG 2
return params;  
}

How can I do this, and still determine the length of the array that I'm creating? I always get '0' on the 'DEBUG 2' printout...

I wrote this piece of code, that should parse the given paramUnparsed (which should be an array in the form: [key1=val1, key2=val2, .., keyn=valn]).

function parseParams(paramUnparsed){
var params = [];
for ( var j = 0; j < paramUnparsed.length; j++) {
    if (paramUnparsed[j].split('=').length < 2) {
        // error ! bad input structure, ignoring params -

        params = undefined;
        break; // we don't have to return error, depending
                // on the function called and given params.

    }
    //else {
        var key = paramUnparsed[j].split('=')[0];
        var value = paramUnparsed[j].split('=')[1];
        params[key] = value;
    //}
}

console.log("In parseParams, params are: "+ concatObject(params));//DEBUG 1
console.log("In parseParams, params length is: "+ params.length);//DEBUG 2
return params;  
}

How can I do this, and still determine the length of the array that I'm creating? I always get '0' on the 'DEBUG 2' printout...

Share Improve this question asked Dec 16, 2011 at 10:42 limlimlimlim 3,1552 gold badges37 silver badges46 bronze badges 0
Add a ment  | 

4 Answers 4

Reset to default 12

The "params" array which is created is an associative array. If you want to get the length of the associative array use

Object.keys(params).length;

You are creating an array, but you are not using it as an array. You are using it as an object, which works as an array is also an object, but it means that the length of the array remains zero as you are not adding any array items.

Create an object, and count the items that you add to get the count:

function parseParams(paramUnparsed){
  var params = {}, cnt = 0;
  for (var j = 0; j < paramUnparsed.length; j++) {
    if (paramUnparsed[j].split('=').length < 2) {
      // error ! bad input structure, ignoring params -

      params = undefined;
      break; // we don't have to return error, depending
             // on the function called and given params.

    }
    var key = paramUnparsed[j].split('=')[0];
    var value = paramUnparsed[j].split('=')[1];
    params[key] = value;
    cnt++;
  }

  console.log("In parseParams, params are: "+ concatObject(params));//DEBUG 1
  console.log("In parseParams, params length is: "+ cnt);//DEBUG 2
  return params;  
}

You're not really building an array. Arrays shouldn't have keys. You can use an object like this:

var params = {};

but that wouldn't solve your .length issue.

What you can also do is building an array of objects, where each object contains a key and value. Something like this:

function parseParams(paramUnparsed){
    var params = [];
    for (var j = 0; j < paramUnparsed.length; j++) {
        if (paramUnparsed[j].split('=').length < 2) {
            params = undefined;
            break;
        }

        var key = paramUnparsed[j].split('=')[0];
        var value = paramUnparsed[j].split('=')[1];
        params.push({ key: key, value: value });
    }

    // use like: `params[0].key` etc

    return params; 
}

Here is some thing odd. This actually holds together.

var arr = [];
arr["test"] = "something";
arr[arr.length]=arr["test"];

Now you have a key value array you kay loop through by key or by index. Also the length property is abailable.

发布评论

评论列表(0)

  1. 暂无评论