iframe-proxy | Sunbelt Computer Software

History

302 lines (267 loc) · 4.49 KB

Raw

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

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

##30 个你不可能全部会做的JavaScript题目

```js

["1","2","3"].map(parseInt)

```

```js

[typeof null, null instanceof Object]

```

```js

[

[3,2,1].resuce(Math.pow),

[].resuce(Math.pow)

]

```

```js

var val = 'smtg';

console.log('Value is '+(val === 'smtg') ? 'Something':'Nothing');

```

```js

var name = 'World';

(function(){

if(typeof name ==="undefined"){

var name = 'Jack';

console.log('Goodbye '+name);

}else{

console.log('Hello '+name);

}

})();

```

```js

//var END = Math.pow(2,53); //9007199254740992

var END = 9007199254740992; //9007199254740992

var START = END - 100;

var count = 0;

for(var i=START;i<=END;i++){

count++;

}

console.log(count);//等了好久没出来结果，即使初始值Math.pow(2,53)已被算好

``````

```js

var ary = [0,1,2];

ary[10] = 10;

ary.filter(function(x){

return x === undefined;

});

```

```js

var two = 0.2;

var one = 0.1;

var eight = 0.8;

var six = 0.6;

[two-one == one,eight-six == two]

```

```js

function showCase(value){

switch(value){

case 'A':

console.log('Case A');

break;

case 'B':

console.log('Case B');

break;

case undefined:

console.log('undefined');

break;

default:

console.log('Do not know!');

}

showCase(new String('A'));

```

10.

```js

续9：

showCase(String('A'));

```

11.

```js

function isOdd(num){

return num%2==1;

}

function isEven(num){

return num%2==0;

}

function isSane(num){

return isEven(num) || isOdd(num);

}

var values = [7,4,'13',-9,-Infinity];

values.map(isSane);

```

12.

```js

parseInt(3,8);

parseInt(3,2);

parseInt(3,0);

```

13.

```js

Array.isArray(Array.prototype)

```

14.

```js

var a = [0];

if([0]){

console.log(a == true);

}else{

console.log('wut');

}

```

15.

```js

[]==[]

```

16.

```js

'5'+3

'5'-3

``````

17.

```js

1+-+++-+1

```

18.

```js

var ary = Array(3);

ary[0]=2;

ary.map(function(elem){

return '1';

})

```

19.

```js

function sidEffecting(ary){

ary[0] = ary[2];

}

function bar(a,b,c){

c=10;

sidEffecting(arguments);

return a+b+c;

}

bar(1,1,1);

```

20.

```js

var a=111111111111111110000,

b=1111;

a+b;

```

21.

```js

var x=[].reveres;

x();

```

22.

```js

Number.MIN_VALUE>0

```

23.

```js

[1<2<3,3<2<1]

```

24.

```js

//the most classic wtf

2==[[[2]]]

```

25.

```js

3.toString();

3..toString();

3...toString();

var num = 3;

num.toString();

num..toString();

num...toString();

```

26.

```js

(function(){

var x=y=1;

})();

console.log(y);

console.log(x);

``````

27.

```js

列举IE与FF脚本兼容性问题，例如：

1 window.event

表示当前对象，IE有这个对象，FF没有

2 获取事件源

IE用srcElement获取事件源，而FF用target获取事件源

3 添加、移除事件

IE：element.attachEvent("onclick",function) element.detachEvent("onclick",function)

FF: element.addEventListener("click",function,true) element.removeEventListener("click",function,true)

请继续增加3项......

```

28.

```js

//以下函数有什么问题？如何改进？

function initButtons(){

var body = document.body,

button,i;

for(i=0;i<5;i++){

button=document.createElement("button");

button.innerHTML="Button "+i;

button.addEventListener("click",function(e){

alert(i);

},false);

body.appendChild(button);

}

function initButtons(){

var body = document.body,

button,i;

for(i=0;i<5;i++){

button=document.createElement("button");

button.innerHTML="Button "+i;

(function(i){

button.addEventListener("click",function(e){

alert(i);

},false);

})(i);

body.appendChild(button);

}

```

29.

```js

写一段代码，判断一个字符床中出现次数最多的字符，并统计出现的次数。

```

30.

```js

//请问一下两端代码有什么不同？

setTimeout(function(){

/* 代码块... */

setTimeout(arguments.callee,10);

},10);

setInterval(function(){

/* 代码块... */

},10);

```

```js

//Add the class of 'threes' to every third row without using a library.

var thirdRows = document.querySelectorAll('tr:nth-of-type(3n)'),

count,

count = thirdRows.length;

for(i = 0; i < count; i++){

thirdRows[i].classList.add('threes');

}

/* old school method */

var rows = document.getElementsByTagName('tr'),

count,

count = rows.length;

for(i = 0; i < count; i += 3){

rows[i].setAttribute('class', 'threes');

}

```

Sunbelt Computer Software

PL/B Language Development and Support

Navigation Menu

Uh oh!

Sunbelt Computer Software

PL/B Language Development and Support

Uh oh!

FilesExpand file tree

30-javascript-test.js

Latest commit

History

30-javascript-test.js

File metadata and controls