012_call和apply区别

一、

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function fn(a,b) {     console.log(this); } fn.call(null,1,2);           //call为参数方式 fn.apply(null,[1,2]);     //apply为数组方式   /*输出=> Object [global] {   DTRACE_NET_SERVER_CONNECTION: [Function],   DTRACE_NET_STREAM_END: [Function],   DTRACE_HTTP_SERVER_REQUEST: [Function],   DTRACE_HTTP_SERVER_RESPONSE: [Function],   DTRACE_HTTP_CLIENT_REQUEST: [Function],   DTRACE_HTTP_CLIENT_RESPONSE: [Function],   global: [Circular],   process:    process {      title: '/usr/local/bin/node',      version: 'v10.3.0',      versions:       { http_parser: '2.8.0',         node: '10.3.0',         v8: '6.6.346.32-node.9',         uv: '1.20.3',         zlib: '1.2.11',         ares: '1.14.0',         modules: '64',         nghttp2: '1.29.0',         napi: '3',         openssl: '1.1.0h',         icu: '61.1',         unicode: '10.0',         cldr: '33.0',         tz: '2018c' },      arch: 'x64',      platform: 'darwin',      release:       { name: 'node',         sourceUrl:          'https://nodejs.org/download/release/v10.3.0/node-v10.3.0.tar.gz',         headersUrl:          'https://nodejs.org/download/release/v10.3.0/node-v10.3.0-headers.tar.gz' },      argv:       [ '/usr/local/Cellar/node/10.3.0/bin/node',         '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs/11.fn.js' ],      execArgv: [],      env:       { PATH:          '/usr/local/opt/openssl/bin:/opt/vagrant/bin:/usr/local/sbin:/usr/local/opt/sqlite/bin:/usr/local/opt/openresty-openssl/bin:/usr/local/opt/icu4c/sbin:/usr/local/mysql/bin:/usr/local/opt/icu4c/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/go/bin:/Applications/Wireshark.app/Contents/MacOS',         NVM_RC_VERSION: '',         FORCE_COLOR: 'true',         ELECTRON_NO_ATTACH_CONSOLE: 'true',         DEBUG_COLORS: 'true',         npm_config_color: 'always',         MOCHA_COLORS: '1',         VERSIONER_PYTHON_VERSION: '2.7',         LOGNAME: 'arunyang',         NVM_NODEJS_ORG_MIRROR: 'https://nodejs.org/dist',         XPC_SERVICE_NAME: 'com.jetbrains.WebStorm.77156',         PWD:          '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs',         NVM_CD_FLAGS: '-q',         NVM_DIR: '/Users/arunyang/.nvm',         SHELL: '/bin/zsh',         PAGER: 'less',         LSCOLORS: 'Gxfxcxdxbxegedabagacad',         SECURITYSESSIONID: '186a8',         OLDPWD: '/Applications/WebStorm.app/Contents/bin',         VERSIONER_PYTHON_PREFER_32_BIT: 'no',         USER: 'arunyang',         ZSH: '/Users/arunyang/.oh-my-zsh',         TMPDIR: '/var/folders/wy/v0w9vkf52836x21w_jz2wzlh0000gn/T/',         SSH_AUTH_SOCK: '/private/tmp/com.apple.launchd.IKTjc3zbdP/Listeners',         XPC_FLAGS: '0x0',         NVM_IOJS_ORG_MIRROR: 'https://iojs.org/dist',         __CF_USER_TEXT_ENCODING: '0x1F5:0x0:0x0',         Apple_PubSub_Socket_Render: '/private/tmp/com.apple.launchd.huBMuc0K3M/Render',         LESS: '-R',         LC_CTYPE: '',         HOME: '/Users/arunyang' },      pid: 3023,      features:       { debug: false,         uv: true,         ipv6: true,         tls_alpn: true,         tls_sni: true,         tls_ocsp: true,         tls: true },      ppid: 2534,      execPath: '/usr/local/Cellar/node/10.3.0/bin/node',      debugPort: 9229,      _startProfilerIdleNotifier: [Function: _startProfilerIdleNotifier],      _stopProfilerIdleNotifier: [Function: _stopProfilerIdleNotifier],      _getActiveRequests: [Function: _getActiveRequests],      _getActiveHandles: [Function: _getActiveHandles],      reallyExit: [Function: reallyExit],      abort: [Function: abort],      chdir: [Function: chdir],      cwd: [Function: cwd],      umask: [Function: umask],      getuid: [Function: getuid],      geteuid: [Function: geteuid],      setuid: [Function: setuid],      seteuid: [Function: seteuid],      setgid: [Function: setgid],      setegid: [Function: setegid],      getgid: [Function: getgid],      getegid: [Function: getegid],      getgroups: [Function: getgroups],      setgroups: [Function: setgroups],      initgroups: [Function: initgroups],      _kill: [Function: _kill],      _debugProcess: [Function: _debugProcess],      _debugEnd: [Function: _debugEnd],      hrtime: [Function: hrtime],      cpuUsage: [Function: cpuUsage],      dlopen: [Function: dlopen],      uptime: [Function: uptime],      memoryUsage: [Function: memoryUsage],      _rawDebug: [Function],      moduleLoadList:       [ 'Binding contextify',         'NativeModule events',         'NativeModule internal/async_hooks',         'NativeModule internal/errors',         'Binding uv',         'Binding buffer',         'Binding async_wrap',         'Binding config',         'Binding icu',         'NativeModule util',         'NativeModule internal/encoding',         'NativeModule internal/util',         'Binding constants',         'Binding util',         'NativeModule internal/util/types',         'Internal Binding types',         'NativeModule buffer',         'NativeModule internal/buffer',         'NativeModule internal/process',         'NativeModule assert',         'NativeModule internal/assert',         'NativeModule fs',         'NativeModule path',         'NativeModule internal/constants',         'Binding fs',         'NativeModule stream',         'NativeModule internal/streams/pipeline',         'NativeModule internal/streams/end-of-stream',         'NativeModule internal/streams/legacy',         'NativeModule _stream_readable',         'NativeModule internal/streams/buffer_list',         'NativeModule internal/streams/destroy',         'NativeModule internal/streams/state',         'NativeModule _stream_writable',         'NativeModule _stream_duplex',         'NativeModule _stream_transform',         'NativeModule _stream_passthrough',         'Binding fs_event_wrap',         'NativeModule internal/fs/utils',         'NativeModule internal/url',         'NativeModule internal/querystring',         'Binding url',         'NativeModule internal/process/warning',         'NativeModule internal/process/next_tick',         'NativeModule internal/process/promises',         'NativeModule internal/fixed_queue',         'NativeModule internal/process/stdio',         'Binding performance',         'Binding trace_events',         'NativeModule internal/inspector_async_hook',         'Binding inspector',         'NativeModule timers',         'Binding timer_wrap',         'NativeModule internal/linkedlist',         'NativeModule internal/timers',         'NativeModule internal/modules/cjs/loader',         'NativeModule vm',         'NativeModule internal/modules/cjs/helpers',         'NativeModule console',         'Binding tty_wrap',         'NativeModule net',         'NativeModule internal/net',         'Binding cares_wrap',         'Binding stream_wrap',         'Binding tcp_wrap',         'Binding pipe_wrap',         'NativeModule internal/stream_base_commons' ],      binding: [Function: binding],      _linkedBinding: [Function: _linkedBinding],      _events:       { newListener: [Function],         removeListener: [Function],         warning: [Function] },      _eventsCount: 3,      _maxListeners: undefined,      _fatalException: [Function],      domain: null,      _exiting: false,      assert: [Function: deprecated],      config: { target_defaults: [Object], variables: [Object] },      setUncaughtExceptionCaptureCallback: [Function],      hasUncaughtExceptionCaptureCallback: [Function],      emitWarning: [Function],      nextTick: [Function: nextTick],      _tickCallback: [Function: _tickCallback],      stdout: [Getter],      stderr: [Getter],      stdin: [Getter],      openStdin: [Function],      exit: [Function],      kill: [Function],      argv0: '/usr/local/bin/node',      mainModule:       Module {         id: '.',         exports: {},         parent: null,         filename:          '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs/11.fn.js',         loaded: false,         children: [],         paths: [Array] } },   Buffer:    { [Function: Buffer]      poolSize: 8192,      from: [Function: from],      of: [Function: of],      alloc: [Function: alloc],      allocUnsafe: [Function: allocUnsafe],      allocUnsafeSlow: [Function: allocUnsafeSlow],      isBuffer: [Function: isBuffer],      compare: [Function: compare],      isEncoding: [Function: isEncoding],      concat: [Function: concat],      byteLength: [Function: byteLength],      [Symbol(kIsEncodingSymbol)]: [Function: isEncoding] },   clearImmediate: [Function: clearImmediate],   clearInterval: [Function: clearInterval],   clearTimeout: [Function: clearTimeout],   setImmediate:    { [Function: setImmediate] [Symbol(util.promisify.custom)]: [Function] },   setInterval: [Function: setInterval],   setTimeout:    { [Function: setTimeout] [Symbol(util.promisify.custom)]: [Function] } } Object [global] {   DTRACE_NET_SERVER_CONNECTION: [Function],   DTRACE_NET_STREAM_END: [Function],   DTRACE_HTTP_SERVER_REQUEST: [Function],   DTRACE_HTTP_SERVER_RESPONSE: [Function],   DTRACE_HTTP_CLIENT_REQUEST: [Function],   DTRACE_HTTP_CLIENT_RESPONSE: [Function],   global: [Circular],   process:    process {      title: '/usr/local/bin/node',      version: 'v10.3.0',      versions:       { http_parser: '2.8.0',         node: '10.3.0',         v8: '6.6.346.32-node.9',         uv: '1.20.3',         zlib: '1.2.11',         ares: '1.14.0',         modules: '64',         nghttp2: '1.29.0',         napi: '3',         openssl: '1.1.0h',         icu: '61.1',         unicode: '10.0',         cldr: '33.0',         tz: '2018c' },      arch: 'x64',      platform: 'darwin',      release:       { name: 'node',         sourceUrl:          'https://nodejs.org/download/release/v10.3.0/node-v10.3.0.tar.gz',         headersUrl:          'https://nodejs.org/download/release/v10.3.0/node-v10.3.0-headers.tar.gz' },      argv:       [ '/usr/local/Cellar/node/10.3.0/bin/node',         '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs/11.fn.js' ],      execArgv: [],      env:       { PATH:          '/usr/local/opt/openssl/bin:/opt/vagrant/bin:/usr/local/sbin:/usr/local/opt/sqlite/bin:/usr/local/opt/openresty-openssl/bin:/usr/local/opt/icu4c/sbin:/usr/local/mysql/bin:/usr/local/opt/icu4c/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/go/bin:/Applications/Wireshark.app/Contents/MacOS',         NVM_RC_VERSION: '',         FORCE_COLOR: 'true',         ELECTRON_NO_ATTACH_CONSOLE: 'true',         DEBUG_COLORS: 'true',         npm_config_color: 'always',         MOCHA_COLORS: '1',         VERSIONER_PYTHON_VERSION: '2.7',         LOGNAME: 'arunyang',         NVM_NODEJS_ORG_MIRROR: 'https://nodejs.org/dist',         XPC_SERVICE_NAME: 'com.jetbrains.WebStorm.77156',         PWD:          '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs',         NVM_CD_FLAGS: '-q',         NVM_DIR: '/Users/arunyang/.nvm',         SHELL: '/bin/zsh',         PAGER: 'less',         LSCOLORS: 'Gxfxcxdxbxegedabagacad',         SECURITYSESSIONID: '186a8',         OLDPWD: '/Applications/WebStorm.app/Contents/bin',         VERSIONER_PYTHON_PREFER_32_BIT: 'no',         USER: 'arunyang',         ZSH: '/Users/arunyang/.oh-my-zsh',         TMPDIR: '/var/folders/wy/v0w9vkf52836x21w_jz2wzlh0000gn/T/',         SSH_AUTH_SOCK: '/private/tmp/com.apple.launchd.IKTjc3zbdP/Listeners',         XPC_FLAGS: '0x0',         NVM_IOJS_ORG_MIRROR: 'https://iojs.org/dist',         __CF_USER_TEXT_ENCODING: '0x1F5:0x0:0x0',         Apple_PubSub_Socket_Render: '/private/tmp/com.apple.launchd.huBMuc0K3M/Render',         LESS: '-R',         LC_CTYPE: '',         HOME: '/Users/arunyang' },      pid: 3023,      features:       { debug: false,         uv: true,         ipv6: true,         tls_alpn: true,         tls_sni: true,         tls_ocsp: true,         tls: true },      ppid: 2534,      execPath: '/usr/local/Cellar/node/10.3.0/bin/node',      debugPort: 9229,      _startProfilerIdleNotifier: [Function: _startProfilerIdleNotifier],      _stopProfilerIdleNotifier: [Function: _stopProfilerIdleNotifier],      _getActiveRequests: [Function: _getActiveRequests],      _getActiveHandles: [Function: _getActiveHandles],      reallyExit: [Function: reallyExit],      abort: [Function: abort],      chdir: [Function: chdir],      cwd: [Function: cwd],      umask: [Function: umask],      getuid: [Function: getuid],      geteuid: [Function: geteuid],      setuid: [Function: setuid],      seteuid: [Function: seteuid],      setgid: [Function: setgid],      setegid: [Function: setegid],      getgid: [Function: getgid],      getegid: [Function: getegid],      getgroups: [Function: getgroups],      setgroups: [Function: setgroups],      initgroups: [Function: initgroups],      _kill: [Function: _kill],      _debugProcess: [Function: _debugProcess],      _debugEnd: [Function: _debugEnd],      hrtime: [Function: hrtime],      cpuUsage: [Function: cpuUsage],      dlopen: [Function: dlopen],      uptime: [Function: uptime],      memoryUsage: [Function: memoryUsage],      _rawDebug: [Function],      moduleLoadList:       [ 'Binding contextify',         'NativeModule events',         'NativeModule internal/async_hooks',         'NativeModule internal/errors',         'Binding uv',         'Binding buffer',         'Binding async_wrap',         'Binding config',         'Binding icu',         'NativeModule util',         'NativeModule internal/encoding',         'NativeModule internal/util',         'Binding constants',         'Binding util',         'NativeModule internal/util/types',         'Internal Binding types',         'NativeModule buffer',         'NativeModule internal/buffer',         'NativeModule internal/process',         'NativeModule assert',         'NativeModule internal/assert',         'NativeModule fs',         'NativeModule path',         'NativeModule internal/constants',         'Binding fs',         'NativeModule stream',         'NativeModule internal/streams/pipeline',         'NativeModule internal/streams/end-of-stream',         'NativeModule internal/streams/legacy',         'NativeModule _stream_readable',         'NativeModule internal/streams/buffer_list',         'NativeModule internal/streams/destroy',         'NativeModule internal/streams/state',         'NativeModule _stream_writable',         'NativeModule _stream_duplex',         'NativeModule _stream_transform',         'NativeModule _stream_passthrough',         'Binding fs_event_wrap',         'NativeModule internal/fs/utils',         'NativeModule internal/url',         'NativeModule internal/querystring',         'Binding url',         'NativeModule internal/process/warning',         'NativeModule internal/process/next_tick',         'NativeModule internal/process/promises',         'NativeModule internal/fixed_queue',         'NativeModule internal/process/stdio',         'Binding performance',         'Binding trace_events',         'NativeModule internal/inspector_async_hook',         'Binding inspector',         'NativeModule timers',         'Binding timer_wrap',         'NativeModule internal/linkedlist',         'NativeModule internal/timers',         'NativeModule internal/modules/cjs/loader',         'NativeModule vm',         'NativeModule internal/modules/cjs/helpers',         'NativeModule console',         'Binding tty_wrap',         'NativeModule net',         'NativeModule internal/net',         'Binding cares_wrap',         'Binding stream_wrap',         'Binding tcp_wrap',         'Binding pipe_wrap',         'NativeModule internal/stream_base_commons' ],      binding: [Function: binding],      _linkedBinding: [Function: _linkedBinding],      _events:       { newListener: [Function],         removeListener: [Function],         warning: [Function] },      _eventsCount: 3,      _maxListeners: undefined,      _fatalException: [Function],      domain: null,      _exiting: false,      assert: [Function: deprecated],      config: { target_defaults: [Object], variables: [Object] },      setUncaughtExceptionCaptureCallback: [Function],      hasUncaughtExceptionCaptureCallback: [Function],      emitWarning: [Function],      nextTick: [Function: nextTick],      _tickCallback: [Function: _tickCallback],      stdout: [Getter],      stderr: [Getter],      stdin: [Getter],      openStdin: [Function],      exit: [Function],      kill: [Function],      argv0: '/usr/local/bin/node',      mainModule:       Module {         id: '.',         exports: {},         parent: null,         filename:          '/Users/00arunalldata00/009_mystudy/010_everest/001_Everest4/20180628/201804/7.fs/11.fn.js',         loaded: false,         children: [],         paths: [Array] } },   Buffer:    { [Function: Buffer]      poolSize: 8192,      from: [Function: from],      of: [Function: of],      alloc: [Function: alloc],      allocUnsafe: [Function: allocUnsafe],      allocUnsafeSlow: [Function: allocUnsafeSlow],      isBuffer: [Function: isBuffer],      compare: [Function: compare],      isEncoding: [Function: isEncoding],      concat: [Function: concat],      byteLength: [Function: byteLength],      [Symbol(kIsEncodingSymbol)]: [Function: isEncoding] },   clearImmediate: [Function: clearImmediate],   clearInterval: [Function: clearInterval],   clearTimeout: [Function: clearTimeout],   setImmediate:    { [Function: setImmediate] [Symbol(util.promisify.custom)]: [Function] },   setInterval: [Function: setInterval],   setTimeout:    { [Function: setTimeout] [Symbol(util.promisify.custom)]: [Function] } } */