funkcja strzałki JavaScript z jednym argumenem
let greet = x => console.log(x);
greet('Hello'); // Hello
SAMER SAEID
let greet = x => console.log(x);
greet('Hello'); // Hellohello = () => {
return "Hello World!";
}// function expression
let x = function(x, y) {
return x * y;
}const power = (base, exponent) => {
let result = 1;
for (let count = 0; count < exponent; count++) {
result *= base;
}
return result;
};
//if the function got only one parameter
const square1 = (x) => { return x * x; };
const square2 = x => x * x;
// empty parameter
const horn = () => {
console.log("Toot");
};//arrow function
()=>{}
//normal function
function(){}
//useses of arrow function
var fnct=()=>{}
var fnct=(param1,param2,...rest)=>{console.log(param1),alert(param2),return(rest)}
//or these
var fnct=e=>{}
var fnct=(e)=>e
var fnct=e=>e
//examples
var fnct=param=>{return 'hello '+param}
var fnct=(param1,param2,...rest)=>!param1?param2:rest
var fnct=return_=>return_
var fnct=hi=>alert(hi)// An empty arrow function returns undefined
let empty = () => {};
(() => 'foobar')();
// Returns "foobar"
// (this is an Immediately Invoked Function Expression)
var simple = a => a > 15 ? 15 : a;
simple(16); // 15
simple(10); // 10
let max = (a, b) => a > b ? a : b;
// Easy array filtering, mapping, ...
var arr = [5, 6, 13, 0, 1, 18, 23];
var sum = arr.reduce((a, b) => a + b);
// 66
var even = arr.filter(v => v % 2 == 0);
// [6, 0, 18]
var double = arr.map(v => v * 2);
// [10, 12, 26, 0, 2, 36, 46]
// More concise promise chains
promise.then(a => {
// ...
}).then(b => {
// ...
});
// Parameterless arrow functions that are visually easier to parse
setTimeout( () => {
console.log('I happen sooner');
setTimeout( () => {
// deeper code
console.log('I happen later');
}, 1);
}, 1);