Get the index of the array element which is an object

Question

I'm new to the JavaScript. Here, I have an array which is like:-

var selected_Text_Include_Array = [{ annotation_Type:'tota',value:'abc',  }]

And it has multiple such objects. Now, Here what I want is to get the id of that specific element.

for (var j = 0; j <= selected_Text_Include_Array.length - 1; j++) {
          if (selected_Text_Include_Array[j].annotation_Type !== "undr") {

            var index = getIndex(selected_Text_Include_Array, annotationName);
            console.log("index is ==>", index);
            if (index !== undefined) {
              selected_Text_Include_Array.splice(index, 1);
            }
          }
        }

Now, Here for getIndex method ,

 var getIndex = function (array, annotationName) {
          if (annotationName === "Address") {
            var index = array.findIndex(function (x) {
              return x.annotation_Type === "foot";
            })
          }
          else if (annotationName === "FootNote") {
            var index = array.findIndex(function (x) {
              return x.annotation_Type === "addr";
            })
          }
          else if (annotationName === "Overview") {
            var index = array.findIndex(function (x) {
              return x.annotation_Type === "tota";
            })
          }
          else if (annotationName === "TotalExperience") {
            var index = array.findIndex(function (x) {
              return x.annotation_Type === "over";
            })
          };
        }

So, with this, the condition gets matches but still it returns the id of that element undefined , I'm not getting why this is happening.

Can any one please help me with this?

Answer 1

I didnt understand very well what you are trying to accomplish but you are not returning the index value form your method.

var getIndex = function (array, annotationName) {
    var index;
    //conditions here and set your index
    return index;
}

Answer 2

I didn't completely understand your code. from your code what I understand is the "annotationName" is not defined in the "for loop" and also you have to initialize the index as "-1" in getIndex function and then update index in each if condition then you have to return the index then only you will get a value. Sample code :

var getIndex = function (array, annotationName) {
    var index =-1;
    if (annotationName === "Address") {
            var index = array.findIndex(function (x) {
              return x.annotation_Type === "foot";
            })
          }
    return index;
}

Answer 3

Change few things in your getIndex function, it will work fine, your code is almost correct, just a return statement missing

You are returning a array index value to "index variable"
and "function getIndex" not returning any value

//add the following statement to at the end of getIndex function before closing "}"

return index;

So your getIndex function becomes like this

 var getIndex = function (array, annotationName) {
     var index;
      if (annotationName === "Address") {
        index = array.findIndex(function (x) {
          return x.annotation_Type === "foot";
        })
      }
      else if (annotationName === "FootNote") {
        index = array.findIndex(function (x) {
          return x.annotation_Type === "addr";
        })
      }
      else if (annotationName === "Overview") {
        index = array.findIndex(function (x) {
          return x.annotation_Type === "tota";
        })
      }
      else if (annotationName === "TotalExperience") {
        index = array.findIndex(function (x) {
          return x.annotation_Type === "over";
        })
      };
      return index;
    }

Note: I am guessing you have array like this

var selected_Text_Include_Array = [{annotation_Type:"over"}, {annotation_Type:'foot'}];

JSBIN Example: https://jsbin.com/qifiday/edit?html,js,console,output