I am trying to make a script which

1. Gets the current URL (url1 variable in the example) which contains params/values and which can be entirely different each time - OK
2. I extract both params and values and create an object from them with keys/values - OK
3. I build a condition for later use, dynamically which does not expect a certain number of pairs, so it gets built from whatever it finds in the object - NOT OK

.

let url1 = 'http://localhost/myproject/results?id=0001&area=eiffel tower&city=Paris&whatever=else';

function URLToArray(url) {
    var request = {};
    var pairs = url.substring(url.indexOf('?')   1).split('&');
    for (var i = 0; i < pairs.length; i  ) {
        if(!pairs[i])
            continue;
        var pair = pairs[i].split('=');
        request[decodeURIComponent(pair[0])] = decodeURIComponent(pair[1]);
     }
     console.log(request); // { id: '0001', area: 'eiffel tower', city: 'Paris', whatever: 'else' }
     return(request);
}

let paramsObj = URLToArray(url1);

console.log(paramsObj)  // { id: '0001', area: 'eiffel tower', city: 'Paris', whatever: 'else' }

// Step 3 below, where the issue is and I expect
// id === '0001' && area === 'eiffel tower' && city === 'Paris' && something === 'else'

paramsObj.forEach((item) => {
  let condition = '';
  let keys = Object.keys(item);
  keys.map((k) => {
    if (condition) {
      condition  = ` && ${k} === '${item[k]}'`
} else {
  condition = `${k} === '${item[k]}'`
    }

  })
  console.log(condition);
})

Outputs

paramsObj.forEach((item) => { TypeError: paramsObj.forEach is not a function at Object.<anonymous>

Expected on console.log(condition)

id === '0001' && area === 'eiffel tower' && city === 'Paris' && whatever === 'else'

Note: if the object was inside [ ] brackets, the output would somehow be the expected one. However URLToArray(url) outputs object without brackets.

CodePudding user response：

ForEach method is an array method and you're trying to use it on an object, you should probably just create a function that takes in an object as one of its parameters.

function ProcessItem(item) {
  let condition = '';
  let keys = Object.keys(item);
  keys.map((k) => {
    if (condition) {
      condition  = ` && ${k} === '${item[k]}'`
    } else {
      condition = `${k} === '${item[k]}'`
    }

  })
  console.log(condition);
}

CodePudding user response：

The URLToArray() returns an object and not an array. You cannot use forEach on an instance of an object.

Instead, you may want to iterate over keys, like the following:

Object.keys(paramsObj).forEach((key) => {
  const value = paramsObj[key];
  let condition = '';
  if (condition) {
    condition  = ` && ${key} == ${value}`;
  } else {
    condition = `${key} == ${value}`;
  }
);

CodePudding user response：

Consider the following.

var url1 = 'http://localhost/myproject/results?id=0001&area=eiffel tower&city=Paris&whatever=else';

function getQueryFromURL(u) {
  var r = {};
  var parts;
  if (u.indexOf("?") > -1) {
    parts = u.substr(u.indexOf("?")   1).split("&");
    $.each(parts, function(i, v) {
      r[v.split("=")[0]] = decodeURI(v.split("=")[1]);
    });
  }
  return r;
}

function objJoin(o, a, b) {
  var r = "";
  var arr;
  $.each(o, function(k, v) {
    if (r.length == 0) {
      r  = [k, a, v].join(" ");
    } else {
      r  = " "   [b, k, a, v].join(" ");
    }
  });
  return r;
}

let paramsObj = getQueryFromURL(url1);

console.log(paramsObj);

console.log(objJoin(paramsObj, "===", "&&"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

This does not do anything vastly different, it just makes a bit better use of the tools at hand to get the same result.