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"version_added": "1"
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"version_added": "1"
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"standard_track": true,
"deprecated": false
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}
},
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"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/break",
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"version_added": "1"
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"safari": {
"version_added": "1"
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"safari_ios": {
"version_added": "1"
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"version_added": "1.0"
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"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
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"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/class",
"spec_url": "https://tc39.es/ecma262/#sec-class-definitions",
"support": {
"chrome": [
{
"version_added": "49"
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{
"version_removed": "49",
"version_added": "42",
"notes": "Strict mode is required."
},
{
"version_removed": "49",
"version_added": "42",
"flags": [
{
"type": "preference",
"name": "Experimental JavaScript",
"value_to_set": "Enabled"
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]
}
],
"chrome_android": [
{
"version_added": "49"
},
{
"version_removed": "49",
"version_added": "42",
"notes": "Strict mode is required."
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{
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"version_added": "42",
"flags": [
{
"type": "preference",
"name": "Experimental JavaScript",
"value_to_set": "Enabled"
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}
],
"edge": {
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},
"firefox": {
"version_added": "45"
},
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"version_added": "45"
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"version_added": false
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{
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"version_added": "29",
"notes": "Strict mode is required."
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{
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"version_added": "29",
"flags": [
{
"type": "preference",
"name": "Experimental JavaScript",
"value_to_set": "Enabled"
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]
}
],
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{
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{
"version_removed": "36",
"version_added": "29",
"notes": "Strict mode is required."
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{
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"version_added": "29",
"flags": [
{
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}
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{
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"version_added": "4.0",
"notes": "Strict mode is required."
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{
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{
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"version_added": "42",
"notes": "Strict mode is required."
}
]
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"const": {
"__compat": {
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/const",
"spec_url": "https://tc39.es/ecma262/#sec-let-and-const-declarations",
"support": {
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"version_added": "21"
},
"chrome_android": {
"version_added": "25"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "36",
"notes": [
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is implemented, but re-assignment is not failing.",
"Prior to Firefox 46, a TypeError
was thrown on redeclaration instead of a SyntaxError
."
]
},
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"version_added": "36",
"notes": [
"Prior to Firefox 13, const
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"Prior to Firefox 46, a TypeError
was thrown on redeclaration instead of a SyntaxError
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]
},
"ie": {
"version_added": "11"
},
"nodejs": {
"version_added": "6.0.0"
},
"opera": {
"version_added": "9"
},
"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "5.1"
},
"safari_ios": {
"version_added": "6"
},
"samsunginternet_android": {
"version_added": "1.5"
},
"webview_android": {
"version_added": "≤37"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"continue": {
"__compat": {
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/continue",
"spec_url": "https://tc39.es/ecma262/#sec-continue-statement",
"support": {
"chrome": {
"version_added": "1"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "1"
},
"firefox_android": {
"version_added": "4"
},
"ie": {
"version_added": "3"
},
"nodejs": {
"version_added": "0.1.100"
},
"opera": {
"version_added": "4"
},
"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "1"
},
"safari_ios": {
"version_added": "1"
},
"samsunginternet_android": {
"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"debugger": {
"__compat": {
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/debugger",
"spec_url": "https://tc39.es/ecma262/#sec-debugger-statement",
"support": {
"chrome": {
"version_added": "5"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "1"
},
"firefox_android": {
"version_added": "4"
},
"ie": {
"version_added": "4"
},
"nodejs": {
"version_added": "0.1.100"
},
"opera": {
"version_added": "10"
},
"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "5"
},
"safari_ios": {
"version_added": "4.2"
},
"samsunginternet_android": {
"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"do_while": {
"__compat": {
"description": "do...while
",
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/do...while",
"spec_url": "https://tc39.es/ecma262/#sec-do-while-statement",
"support": {
"chrome": {
"version_added": "1"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "1"
},
"firefox_android": {
"version_added": "4"
},
"ie": {
"version_added": "4"
},
"nodejs": {
"version_added": "0.1.100"
},
"opera": {
"version_added": "4"
},
"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "1"
},
"safari_ios": {
"version_added": "1"
},
"samsunginternet_android": {
"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"empty": {
"__compat": {
"description": "Empty statement (;
)",
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/Empty",
"spec_url": "https://tc39.es/ecma262/#sec-empty-statement",
"support": {
"chrome": {
"version_added": "3"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "1"
},
"firefox_android": {
"version_added": "4"
},
"ie": {
"version_added": "3"
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"nodejs": {
"version_added": "0.1.100"
},
"opera": {
"version_added": "3"
},
"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "5"
},
"safari_ios": {
"version_added": "4.2"
},
"samsunginternet_android": {
"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"export": {
"__compat": {
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/export",
"spec_url": "https://tc39.es/ecma262/#sec-exports",
"support": {
"chrome": {
"version_added": "61"
},
"chrome_android": {
"version_added": "61"
},
"edge": [
{
"version_added": "16"
},
{
"version_added": "15",
"flags": [
{
"name": "Experimental JavaScript Features",
"type": "preference"
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]
}
],
"firefox": [
{
"version_added": "60"
},
{
"version_added": "54",
"version_removed": "60",
"flags": [
{
"name": "dom.moduleScripts.enabled",
"type": "preference"
}
]
}
],
"firefox_android": [
{
"version_added": "60"
},
{
"version_added": "54",
"version_removed": "60",
"flags": [
{
"name": "dom.moduleScripts.enabled",
"type": "preference"
}
]
}
],
"ie": {
"version_added": false
},
"nodejs": [
{
"version_added": "13.2.0",
"notes": "Modules must either have a filename ending in .mjs
, or the nearest parent package.json
file must contain \"type\": \"module\"
. See Node's ECMAScript Modules documentation for more details."
},
{
"version_added": "12.0.0",
"flags": [
{
"name": "--experimental-modules",
"type": "runtime_flag"
}
],
"notes": "Modules must either have a filename ending in .mjs
, or the nearest parent package.json
file must contain \"type\": \"module\"
. See Node's ECMAScript Modules documentation for more details."
},
{
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"flags": [
{
"name": "--experimental-modules",
"type": "runtime_flag"
}
],
"notes": "Module filenames must end with .mjs
, not .js. See Node's ECMAScript Modules documentation for more details."
}
],
"opera": {
"version_added": "48"
},
"opera_android": {
"version_added": "45"
},
"safari": {
"version_added": "10.1"
},
"safari_ios": {
"version_added": "10.3"
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"samsunginternet_android": {
"version_added": "8.0"
},
"webview_android": {
"version_added": false
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
},
"default": {
"__compat": {
"description": "default
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",
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/default",
"spec_url": "https://tc39.es/ecma262/#sec-exports",
"support": {
"chrome": {
"version_added": "61"
},
"chrome_android": {
"version_added": "61"
},
"edge": [
{
"version_added": "16"
},
{
"version_added": "15",
"flags": [
{
"name": "Experimental JavaScript Features",
"type": "preference"
}
]
}
],
"firefox": [
{
"version_added": "60"
},
{
"version_added": "54",
"version_removed": "60",
"flags": [
{
"name": "dom.moduleScripts.enabled",
"type": "preference"
}
]
}
],
"firefox_android": [
{
"version_added": "60"
},
{
"version_added": "54",
"version_removed": "60",
"flags": [
{
"name": "dom.moduleScripts.enabled",
"type": "preference"
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]
}
],
"ie": {
"version_added": false
},
"nodejs": [
{
"version_added": "13.2.0",
"notes": "Modules must either have a filename ending in .mjs
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},
{
"version_added": "12.0.0",
"flags": [
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"name": "--experimental-modules",
"type": "runtime_flag"
}
],
"notes": "Modules must either have a filename ending in .mjs
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},
{
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"flags": [
{
"name": "--experimental-modules",
"type": "runtime_flag"
}
],
"notes": "Module filenames must end with .mjs
, not .js. See Node's ECMAScript Modules documentation for more details."
}
],
"opera": {
"version_added": "48"
},
"opera_android": {
"version_added": "45"
},
"safari": {
"version_added": "10.1"
},
"safari_ios": {
"version_added": "10.3"
},
"samsunginternet_android": {
"version_added": "8.0"
},
"webview_android": {
"version_added": false
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"namespace": {
"__compat": {
"description": "export * as namespace
",
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/export",
"spec_url": "https://tc39.es/ecma262/#sec-exports",
"support": {
"chrome": {
"version_added": "72"
},
"chrome_android": {
"version_added": "72"
},
"edge": {
"version_added": "79"
},
"firefox": {
"version_added": "80"
},
"firefox_android": {
"version_added": false
},
"ie": {
"version_added": false
},
"nodejs": {
"version_added": "12.0.0"
},
"opera": {
"version_added": "60"
},
"opera_android": {
"version_added": "51"
},
"safari": {
"version_added": false
},
"safari_ios": {
"version_added": false
},
"samsunginternet_android": {
"version_added": "11.0"
},
"webview_android": {
"version_added": false
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
}
},
"for": {
"__compat": {
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/for",
"spec_url": "https://tc39.es/ecma262/#sec-for-statement",
"support": {
"chrome": {
"version_added": "1"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "1"
},
"firefox_android": {
"version_added": "4"
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"nodejs": {
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"opera": {
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"version_added": "10.1"
},
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"version_added": "1"
},
"safari_ios": {
"version_added": "1"
},
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"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"for_await_of": {
"__compat": {
"description": "for await...of
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"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/for-await...of",
"spec_url": "https://tc39.es/ecma262/#sec-for-in-and-for-of-statements",
"support": {
"chrome": {
"version_added": "63"
},
"chrome_android": {
"version_added": "63"
},
"edge": {
"version_added": "79"
},
"firefox": {
"version_added": "57"
},
"firefox_android": {
"version_added": "57"
},
"ie": {
"version_added": false
},
"nodejs": [
{
"version_added": "10.0.0"
},
{
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"version_removed": "10.0.0",
"flags": [
{
"type": "runtime_flag",
"name": "--harmony-async-iteration"
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]
}
],
"opera": {
"version_added": "50"
},
"opera_android": {
"version_added": "46"
},
"safari": {
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},
"safari_ios": {
"version_added": "11"
},
"samsunginternet_android": {
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"webview_android": {
"version_added": "63"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
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}
},
"for_in": {
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"description": "for...in
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"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/for...in",
"spec_url": "https://tc39.es/ecma262/#sec-for-in-and-for-of-statements",
"support": {
"chrome": {
"version_added": "1"
},
"chrome_android": {
"version_added": "18"
},
"edge": {
"version_added": "12"
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"firefox": {
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"firefox_android": {
"version_added": "4"
},
"ie": {
"version_added": "6"
},
"nodejs": {
"version_added": "0.1.100"
},
"opera": {
"version_added": "2"
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"opera_android": {
"version_added": "10.1"
},
"safari": {
"version_added": "1"
},
"safari_ios": {
"version_added": "1"
},
"samsunginternet_android": {
"version_added": "1.0"
},
"webview_android": {
"version_added": "1"
}
},
"status": {
"experimental": false,
"standard_track": true,
"deprecated": false
}
}
},
"for_of": {
"__compat": {
"description": "for...of
",
"mdn_url": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Statements/for...of",
"spec_url": "https://tc39.es/ecma262/#sec-for-in-and-for-of-statements",
"support": {
"chrome": {
"version_added": "38"
},
"chrome_android": {
"version_added": "38"
},
"edge": {
"version_added": "12"
},
"firefox": {
"version_added": "13",
"notes": "Prior to Firefox 51, using the for...of
loop construct with the const
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(\"missing = in const declaration\")."
},
"firefox_android": {
"version_added": "14",
"notes": "Prior to Firefox 51, using the for...of
loop construct with the const
keyword threw a SyntaxError
(\"missing = in const declaration\")."
},
"ie": {
"version_added": false
},
"nodejs": {
"version_added": "0.12"
},
"opera": {
"version_added": "25"
},
"opera_android": {
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