いくつかのJavaScript奇技淫巧
1989 ワード
#1
, var a = b || 123;
var a = b == 123;
#2
!!a
#3
iframe
if(top !== window) {
top.location.href = window.location.href;
}
#4
arguments
function args() {
return [].slice.call(arguments, 0);
}
args(2, 5, 0); //[2, 5, 0]
#5
var arr = [2, 3, 45, 12, 8];
Math.max.apply(null, arr); //45
#6
NaN
NaN === NaN; // false
#7
0.81 * 10 8.100000000000001,JS ,
0.81 * 100 * 10 / 100
( )
(0.81 * 10).toFixed(1)
#8
配列mからn個の値をランダムに取り出し、コードを見ます.
var m = [1,2,3,4,5,6,7,8,9,'a','b','c','d','e','#'];
function randArray(m, len) {
m.sort(function () {
return Math.random() - 0.5;
});
return m.slice(0, len);
}
console.log(randArray(m, 4));