Question

Lets say I have an array of names for a variable:

var varNames = new Array("name1","name2","name3");

How do I create var name1, var name2 and var name3 by just looping through the varNames array?

Answer 1

This will create global variables (in the global namespace, i.e. window).

var varNames = ["name1","name2","name3"];
for (var i=0;i<varNames.length;i+=1){
  window[varNames[i]] = 0;
}
name1; //=> 0

Since using global variables is considered bad practice, you could create variables within a custum object:

var myVariables = {}
   ,varNames = ["name1","name2","name3"];
for (var i=0;i<varNames.length;i+=1){
  myVariables[varNames[i]] = 0;
}
myVariables.name1; //=> 0

[ES20xx]

const myVariables = ['name1', 'name2', 'name3']
  .reduce( (a, v, i) => ({...a, [v]: i + 1 }), {});

console.log(JSON.stringify(myVariables, null, 2));

// to 'global' variables
Object.entries(myVariables).forEach( ([key, value]) =>
  window[key] = value );
  
console.log(`name1: ${name1}, name2: ${name2}`);