Is there any difference in JSON Key when using single quote and double quote?

double-quotes, javascript, json

Solution

In JSON only double quotes are valid.

You can find the standard on JSON.org

A value can be a string in double quotes, or a number, or true or false or null, or an object or an array. These structures can be nested.

In other words, no strings in single quotes.

Problem

I ran two pieces of javascript codes in a online JS running platform:Website Link ``` pets = '{'pet_names':[{"name":"jack"},{"name":"john"},{"name":"joe"}]}'; var arr = JSON.parse(pets); alert(arr.pet_names[1].name); ``` Code with double quotes ("pet_names") would be OK but with single quotes('pet_names') would remind a error:"Unexpected identifier" ``` pets = '{"pet_names":[{"name":"jack"},{"name":"john"},{"name":"joe"}]}'; var arr = JSON.parse(pets); alert(arr.pet_names[1].name); ``` So, why do it would happen?

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