How JSON is used and how it differs from arrays

A brief introduction to JSON, the full name is JavaScript Object Notation. It is a lightweight data interchange format based on the JavaScript programming language ECMA-262 3rd Edition-december 1999 standard, mainly used for exchanging data with the server. Similar to XML, its independent language has a great advantage in cross-platform data transmission.

alert (JSON.A);

Alert (json[' a ']); the second way to take the value of//JSON.A.

Alert (arr[0]);

Array Loop method One: (using the I-length method)

for (Var i=0;i<arr.length;i++)

{alert (' +i+ ' thing: ' +arr[i]);}

Array loop The second method: for in (using the For in method)

for (var i in arr) {alert (' +i+ ' thing: ' +arr[i]); }

Note: Because JSON has no length, the first method of taking length does not work, only the second method

for (var i in JSON)

{

Alert (' +i+ ' thing: ' +json[i]);

}

How JSON is used and how it differs from arrays