Tips and tricks to make the most of JavaScript and avoid gotchas.
Joined May 2016
- Tweets 37
- Following 328
- Followers 335
- Likes 198
Photos and videos
7 Jul 2016
Arrow functions are not yet supported in Safari, IE and Opera Mini. #javascript #es6 #tip
caniuse.com/#feat=arrow-func…
1
5
6 Jul 2016
// ES5
var posNums = nums.filter(function (x) {
return x > 0;
});
// #ES6
var posNums = nums.filter(x => x > 0);
#javascript #tip
2
3
6 Jul 2016
#ES6 arrow functions do not have their own 'this'. The value of this inside an arrow function is always inherited from the enclosing scope.
2
5
JavaScript Tips retweeted
4 Jul 2016
Code is temporary. It exists while it is useful.
If code is replaced by better code, good!
If code can be deleted, celebrate! #JavaScript
3
94
173
5 Jul 2016
Shorthand for #es6 arrow function with single argument:
var f = x => {
return x*x;
};
// equivalent to
var f = (x) => {
return x*x;
};
1
2
1
5 Jul 2016
Shorthand for #es6 arrow function with single return statement:
var f = (x) => x*x;
// equivalent to
var f = (x) => {
return x*x;
};
1
2 Jul 2016
ES6 arrow functions:
var normalFunc = function(x) {
return x * x;
};
var arrowFunc = (x) => {
return x*x;
};
#javascript #tips
5
5
1 Jul 2016
#javascript 'new' keyword:
function A() {
this.x = 1;
this.y = 2;
}
var a1 = new A();
var a2 = new A();
a1.x ;
a1.x; // 2
a2.x; // 1
3
5
1 Jul 2016
Usage of the 'arguments' local variable:
function foo() {
console.log(arguments);
}
foo(1, 2, 3, 4); // [1, 2, 3, 4]
#javascript #tip
1
30 Jun 2016
3
2 Jun 2016
Convert CSV to array:
var str = "apple, peach, orange";
var fruitsArray = str.split(","); // ['apple', 'peach', 'orange']
#javascript #tip
3
2 Jun 2016
#JavaScript array to csv:
var fruits = ['apple', 'peaches', 'oranges'];
var str = fruits.valueOf();
// apple,peaches,oranges
#js #tips
3
2 Jun 2016
Remove duplicates from array:
var deduped = [ 1, 1, 'a', 'a'].filter(function (x, i, arr) {
return arr.indexOf(x) === i;
}); // [1, 'a']
1
1
2 Jun 2016
Flattening an array :
var myArray = [[1, 2], [], [3]];
var flatArray = [].concat.apply([], myArray);
// flatArray is [1, 2, 3]
#javascript
1
2
2 Jun 2016
Getting a UNIX timestamp in #JavaScript:
var dateTime = Date.now();
var timestamp = Math.floor(dateTime / 1000);
#tips #js
1
2 Jun 2016
To see a function's code, concatenate it with the empty string :
console.log(funcVariable '');
#javascript #tips
2 Jun 2016
The && operator first evaluates the expression on the left. If falsy, false is returned; it does not bother to evaluate the right operand.
1
2 Jun 2016
JavaScript Falsy Values: null, false, 0 undefined, NaN, and “” (this last item is an empty string). #javascript #tips
2 Jun 2016
Infinity, which is a special number like NaN, is truthy; it is not falsy, while NaN is falsy. #javascript #tips
1 Jun 2016
Calculate max/min in an array:
var arr = [1, 2, 3, 4];
Math.max.apply(null, arr) // 4
Math.min.apply(null, arr) // 1
#javascript #tips
1