CODEWITHSUNDEEP
javascriptarraysliteralsstring-literals
dev.e.loper
dev.e.loper

Reputation: 36044

Convert javascript string to an array

I'm retrieving an array of objects from a hidden html input field. The string I'm getting is: 

"{"id":"1234","name":"john smith","email":"[email protected]"},{"id":"4431","name":"marry doe","email":"[email protected]"}"

Now I need to pass this as an array of objects again. How do I convert this string into array of objects?

Upvotes: 5

Views: 19118

Answers (4)

Sándor Krisztián
Sándor Krisztián

Reputation: 699

There are many bad formatted string object, GET from API, old code, etc. Bad format doesn't means it drops error in code, but drops error for input of JSON.parse().

// not " wrapped key syntax
var str = "{ a: 2 }";
console.log( JSON.parse( str ) );
//  SyntaxError: JSON.parse: expected property name or '}' at line 1 column 3 of the JSON data

// 'key', or 'value' syntax
var str = " { 'a': 2 } ";
console.log( JSON.parse( str ) );
// SyntaxError: JSON.parse: expected property name or '}' at line 1 column 3 of the JSON data

//syntax OK
var str = '{ "a": 2 }';
console.log( JSON.parse( str ) );
// Object { a: 2 }

There is a solution:

// Convert any-formatted object string to well formatted object string:
var str = "{'a':'1',b:20}";
console.log( eval( "JSON.stringify( " + str + ", 0, 1 )" ) );

/* 
"{
 "a": "1",
 "b": 20
}"
*/

// Convert any-formatted object string to object:
console.log( JSON.parse(  eval( "JSON.stringify( " + str + ", 0, 1 )" ) ) );
// Object { a: "1", b: 20 }

Upvotes: 1

hadi.sh
hadi.sh

Reputation: 129

var str=eval([{'id':'1','txt':'name1'},{'id':'2','txt':'name2'},{'id':'3','txt':'name3'}])
for(var i=0;i<str.length;i++)
{
alert(str[i].txt);
}

Upvotes: 0

Gordon Gustafson
Gordon Gustafson

Reputation: 41209

var array_of_objects = eval("[" + my_string + "]");

This executes the string as code, which is why we need to add the [] to make it an object. This is also one of the few legitimate uses for eval as its the fastest and easiest way. :D

Upvotes: 14

SLaks
SLaks

Reputation: 887413

Assuming that str holds valid JSON syntax, you can simply call eval(str).

For security reasons, it's better to use a JSON parser, like this:

JSON.parse(str);

Note that str must be wrapped in [] to be a valid JSON array.

Upvotes: 9

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