JavaScript: slice object name

Question

"course_DxhYTv2copzWyBhKo" : {
    "interest" : "DxhYTv2copzWyBhKo",
    "type" : "course",
    "affinity" : 3
}

From Object Name "course_DxhYTv2copzWyBhKo", I want to slice "DxhYTv2copzWyBhKo"

Answer 1

Using String#split:

const data = {
  "course_DxhYTv2copzWyBhKo" : {
    "interest" : "DxhYTv2copzWyBhKo",
    "type" : "course",
    "affinity" : 3
  }
};

const key = Object.keys(data)[0];
const sliceAfterSubStr = "course_";

const slicedSubStr = key.split(sliceAfterSubStr)[1];

console.log(slicedSubStr);

Using String#substr:

const data = {
  "course_DxhYTv2copzWyBhKo" : {
    "interest" : "DxhYTv2copzWyBhKo",
    "type" : "course",
    "affinity" : 3
  }
};

const key = Object.keys(data)[0];
const sliceAfterSubStr = "course_";
const sliceIndex = key.indexOf(sliceAfterSubStr);

const slicedSubStr = sliceIndex !== -1
  ? key.substr( sliceIndex + sliceAfterSubStr.length )
  : undefined;

console.log(slicedSubStr);

Answer 2

You can use the split operation on a string. Take a look at the following code snippet.

const courses = {
  "course_DxhYTv2copzWyBhKo": {
    "interest": "DxhYTv2copzWyBhKo",
    "type": "course",
    "affinity": 3
  },
  "course_DSdasdnDASnoiddDs": {
    "interest": "DSdasdnDASnoiddDs",
    "type": "course",
    "affinity": 3
  }
}

console.log(Object.keys(courses).map(key => key.split("_")[1]))