javascript using the unary-plus and unary-minus operator一元操作子
4317 ワード
初心者入門ですね.見れば分かります.
<
script src
=
'
jquery.js
'
><
/
script>
......
<
script
>
var
a
=
1
;
var
b
=
'
2
'
;
//
output number
console.log(
typeof
(
-
b));
console.log(
typeof
(
+
b));
//
output string
console.log(
typeof
(b));
//
output 12
console.log(a
+
b);
//
output 3
console.log(a
+
Number(b));
console.log(a
+
+
b);
console.log(a
-
-
b);
//
output -1
console.log(a
+
-
b);
console.log(a
-
+
b);
<
/
script>