Created
October 1, 2014 05:55
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JavaScript noodling
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> var foo = function (a) { return function (b) { return a * b; }; }; | |
undefined | |
> var bar = foo(2); | |
undefined | |
> bar(5); | |
10 | |
> var foo = function () { console.log(arguments.length); }; | |
undefined | |
> foo(); | |
0 | |
undefined | |
> foo(true); | |
1 | |
undefined | |
> foo(true, 1); | |
2 | |
undefined | |
> var foo = function () { console.log(arguments[1]); }; | |
undefined | |
> foo(true, 1); | |
1 | |
undefined | |
> [1, 2, 3].slice(1, 2); | |
[ 2 ] | |
> [1, 2, 3, 4, 5].slice(1, 2); | |
[ 2 ] | |
> [1, 2, 3, 4, 5].slice(1, 4); | |
[ 2, 3, 4 ] | |
> [1, 2, 3, 4, 5].slice(); | |
[ 1, 2, 3, 4, 5 ] | |
> var foo = { a: function () { console.log(this.b); }; | |
... | |
> var foo = { a: function () { console.log(this.b); } }; | |
undefined | |
> foo; | |
{ a: [Function] } | |
> foo.(); | |
... | |
> foo.a(); | |
undefined | |
undefined | |
> var bar = { b: true }; | |
undefined | |
> foo.a.apply(bar); | |
true | |
undefined | |
> var foo = { a: function (c, d, e) { console.log(this.b); console.(d); } }; | |
... | |
> var foo = { a: function (c, d, e) { console.log(this.b); console.log(d); } }; | |
undefined | |
> foo.a.apply(bar, [1, 2, 3]); | |
true | |
2 | |
undefined | |
> foo.a.call(bar, 1, 2, 3); | |
true | |
2 | |
undefined | |
> var foo = function () { }; | |
undefined | |
> [1, 2, 3].slice(); | |
[ 1, 2, 3 ] | |
> var foo = function () { var args = Array.prototype.slice.apply(arguments); }; | |
undefined | |
> var foo = function () { var args = Array.prototype.slice.apply(arguments); var arg = args.pop(); }; | |
undefined | |
> var foo = function () { var args = Array.prototype.slice.apply(arguments); var arg = args.pop(); console.log(arg); }; | |
undefined | |
> foo(a, b, c); | |
ReferenceError: a is not defined | |
at repl:1:5 | |
at REPLServer.self.eval (repl.js:110:21) | |
at repl.js:249:20 | |
at REPLServer.self.eval (repl.js:122:7) | |
at Interface.<anonymous> (repl.js:239:12) | |
at Interface.emit (events.js:95:17) | |
at Interface._onLine (readline.js:202:10) | |
at Interface._line (readline.js:531:8) | |
at Interface._ttyWrite (readline.js:760:14) | |
at ReadStream.onkeypress (readline.js:99:10) | |
> foo(true, false 2112); | |
... | |
> foo(true, false, 2112); | |
2112 | |
undefined | |
> | |
undefined | |
> | |
undefined | |
> | |
undefined | |
> var foo = function () { var args = Array.prototype.slice.apply(arguments); return function (a) { args.push(a); console.log(args) }; }; | |
undefined | |
> foo(); | |
[Function] | |
> foo(1, 2, 3); | |
[Function] | |
> var bar = foo(1, 2, 3); | |
undefined | |
> bar(4); | |
[ 1, 2, 3, 4 ] | |
undefined | |
> var bar = foo(1, 2, 3); |
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