I was making a weather thing using weather.gov API and when I used this code I got an error.

Error:

Uncaught SyntaxError: Lexical declaration cannot appear in a single-statement context

Code:

$.getJSON("https://api.weather.gov/gridpoints/DTX/49,12/forecast", function(data) {
    for (var i = 0; i == 14; i++) {
        if(data['properties']['periods'][i]['name'] == 'Tonight')
        let ex = data['properties']['periods'][i]
    }
});

Every time I look this up I get discord stuff.