存档

文章标签 ‘javascript’

JavaScript中的数据类型转换

2017/10/03 5,142

这里总结了JavaScript中常见的数据类型转换

1 字符串 to 数值

显式转换

通常的做法是使用 Number()，parseInt() , parseFloat() 函数。需要注意的是， Number() 的参数不能含有非数字字符串值 ，如 Number(100x) 会得到 Nan， 而 parseInt(), parseFloat() 则是参数的第一个字符不可以是非数字，否则会得到 Nan, 而且它会忽略第一个非数字的字符串之后的所有字符。

对于 parseInt() 函数来说，可以指定进制。早期版本的 JavaScript 默认执行 8 进制转换，而新版本使用 10 进制 进行转换。如果需要保证兼容性，则需要带上第二个参数：

隐式转换

数值的字符串变量(指可以通过 Number函数转换为数值的字符串，本节中的字符串均指可以通过 Number() 转换为数值的字符串) 在遇到数值运算符时可能发生隐式转换:
继续阅读

Note ,

javascript 实现文本到 emoji 的转换

2017/03/15 6,238

实际上这就是一个将文字转换为对应的图像并在前端显示出来的过程

目前所有的 emoji 与文件的对应关系定义如下：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
var emoji={"[大笑]":{file:"emoji_0.png"},
"[可爱]":{file:"emoji_01.png"},
"[色]":{file:"emoji_02.png"},
"[嘘]":{file:"emoji_03.png"},
"[亲]":{file:"emoji_04.png"},
"[呆]":{file:"emoji_05.png"},
"[口水]":{file:"emoji_06.png"},
"[汗]":{file:"emoji_145.png"},
"[呲牙]":{file:"emoji_07.png"},
"[鬼脸]":{file:"emoji_08.png"},
"[害羞]":{file:"emoji_09.png"},
"[偷笑]":{file:"emoji_10.png"},
"[调皮]":{file:"emoji_11.png"},
"[可怜]":{file:"emoji_12.png"},
"[敲]":{file:"emoji_13.png"},
"[惊讶]":{file:"emoji_14.png"},
"[流感]":{file:"emoji_15.png"},
"[委屈]":{file:"emoji_16.png"},
"[流泪]":{file:"emoji_17.png"},
"[嚎哭]":{file:"emoji_18.png"},
"[惊恐]":{file:"emoji_19.png"},
"[怒]":{file:"emoji_20.png"},
"[酷]":{file:"emoji_21.png"},
"[不说]":{file:"emoji_22.png"},
"[鄙视]":{file:"emoji_23.png"},
"[阿弥陀佛]":{file:"emoji_24.png"},
"[奸笑]":{file:"emoji_25.png"},
"[睡着]":{file:"emoji_26.png"},
"[口罩]":{file:"emoji_27.png"},
"[努力]":{file:"emoji_28.png"},
"[抠鼻孔]":{file:"emoji_29.png"},
"[疑问]":{file:"emoji_30.png"},
"[怒骂]":{file:"emoji_31.png"},
"[晕]":{file:"emoji_32.png"},
"[呕吐]":{file:"emoji_33.png"},
"[拜一拜]":{file:"emoji_160.png"},
"[惊喜]":{file:"emoji_161.png"},
"[流汗]":{file:"emoji_162.png"},
"[卖萌]":{file:"emoji_163.png"},
"[默契眨眼]":{file:"emoji_164.png"},
"[烧香拜佛]":{file:"emoji_165.png"},
"[晚安]":{file:"emoji_166.png"},
"[强]":{file:"emoji_34.png"},
"[弱]":{file:"emoji_35.png"},
"[OK]":{file:"emoji_36.png"},
"[拳头]":{file:"emoji_37.png"},
"[胜利]":{file:"emoji_38.png"},
"[鼓掌]":{file:"emoji_39.png"},
"[握手]":{file:"emoji_200.png"},
"[发怒]":{file:"emoji_40.png"},
"[骷髅]":{file:"emoji_41.png"},
"[便便]":{file:"emoji_42.png"},
"[火]":{file:"emoji_43.png"},
"[溜]":{file:"emoji_44.png"},
"[爱心]":{file:"emoji_45.png"},
"[心碎]":{file:"emoji_46.png"},
"[钟情]":{file:"emoji_47.png"},
"[唇]":{file:"emoji_48.png"},
"[戒指]":{file:"emoji_49.png"},
"[钻石]":{file:"emoji_50.png"},
"[太阳]":{file:"emoji_51.png"},
"[有时晴]":{file:"emoji_52.png"},
"[多云]":{file:"emoji_53.png"},
"[雷]":{file:"emoji_54.png"},
"[雨]":{file:"emoji_55.png"},
"[雪花]":{file:"emoji_56.png"},
"[爱人]":{file:"emoji_57.png"},
"[帽子]":{file:"emoji_58.png"},
"[皇冠]":{file:"emoji_59.png"},
"[篮球]":{file:"emoji_60.png"},
"[足球]":{file:"emoji_61.png"},
"[垒球]":{file:"emoji_62.png"},
"[网球]":{file:"emoji_63.png"},
"[台球]":{file:"emoji_64.png"},
"[咖啡]":{file:"emoji_65.png"},
"[啤酒]":{file:"emoji_66.png"},
"[干杯]":{file:"emoji_67.png"},
"[柠檬汁]":{file:"emoji_68.png"},
"[餐具]":{file:"emoji_69.png"},
"[汉堡]":{file:"emoji_70.png"},
"[鸡腿]":{file:"emoji_71.png"},
"[面条]":{file:"emoji_72.png"},
"[冰淇淋]":{file:"emoji_73.png"},
"[沙冰]":{file:"emoji_74.png"},
"[生日蛋糕]":{file:"emoji_75.png"},
"[蛋糕]":{file:"emoji_76.png"},
"[糖果]":{file:"emoji_77.png"},
"[葡萄]":{file:"emoji_78.png"},
"[西瓜]":{file:"emoji_79.png"},
"[光碟]":{file:"emoji_80.png"},
"[手机]":{file:"emoji_81.png"},
"[电话]":{file:"emoji_82.png"},
"[电视]":{file:"emoji_83.png"},
"[声音开启]":{file:"emoji_84.png"},
"[声音关闭]":{file:"emoji_85.png"},
"[铃铛]":{file:"emoji_86.png"},
"[锁头]":{file:"emoji_87.png"},
"[放大镜]":{file:"emoji_88.png"},
"[灯泡]":{file:"emoji_89.png"},
"[锤头]":{file:"emoji_90.png"},
"[烟]":{file:"emoji_91.png"},
"[炸弹]":{file:"emoji_92.png"},
"[枪]":{file:"emoji_93.png"},
"[刀]":{file:"emoji_94.png"},
"[药]":{file:"emoji_95.png"},
"[打针]":{file:"emoji_96.png"},
"[钱袋]":{file:"emoji_97.png"},
"[钞票]":{file:"emoji_98.png"},
"[银行卡]":{file:"emoji_99.png"},
"[手柄]":{file:"emoji_100.png"},
"[麻将]":{file:"emoji_101.png"},
"[调色板]":{file:"emoji_102.png"},
"[电影]":{file:"emoji_103.png"},
"[麦克风]":{file:"emoji_104.png"},
"[耳机]":{file:"emoji_105.png"},
"[音乐]":{file:"emoji_106.png"},
"[吉他]":{file:"emoji_107.png"},
"[火箭]":{file:"emoji_108.png"},
"[飞机]":{file:"emoji_109.png"},
"[火车]":{file:"emoji_110.png"},
"[公交]":{file:"emoji_111.png"},
"[轿车]":{file:"emoji_112.png"},
"[出租车]":{file:"emoji_113.png"},
"[警车]":{file:"emoji_114.png"},
"[自行车]":{file:"emoji_115.png"}};

使用正则表达式替换成文件，代码如下：

1
2
3
4
5
6
7
8
9
10
function buildEmoji(text) {
    var re =  /\[([^\]\[]*)\]/g;
    var matches = text.match(re) || [];
    for (var j = 0, len = matches.length; j < len; ++j) {
        if(emoji[matches[j]]){
            text = text.replace(matches[j], '<img class="emoji" src="../static/modules/message/images/emoji/' + emoji[matches[j]].file + '" />');
        }
    }
    return text;
}

 

并定义出相应的 style 即可。

用到的 emoji 图片与 js 文件可以在这里下载

 

Tinynote