SOURCE

var str = '["a", "b", "c", "d"]';
var arr =  eval('(' + str + ')');
console.log(arr[0],'arr',arr)
var str1 = '["a", "b", "c", "d"]';
var arr1 =  JSON.parse(str);
console.log(arr1[0],'arr',arr1)
let arr2 = [{a:1,b:1},{a:2,b:1},{a:3,b:1}]
let tr ="'"+arr2+"'"
console.log(tr,'tr')