const

Declares a constant with block level scope

Other: https://tc39.es/ecma262/#sec-let-and-const-declarations

Usage: 95.7% + 0.61% = 96.3%

Support summary

Notes

  1. const is recognized, but treated like var (no block scope, can be overwritten)
  2. const does not have block scope
  3. Only recognized when NOT in strict mode
  4. Supported correctly in strict mode, otherwise supported without block scope
  5. Not supported in for-in and for-of loops

Links

Full support table

IE

5.567891011
nnnnnna

Edge

121314151617187980818384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141
yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Firefox

233.53.6456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Chrome

4567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Safari

3.13.2455.166.177.1899.11010.11111.11212.11313.11414.11515.115.2-15.315.415.515.616.016.116.216.316.416.516.617.017.117.217.317.417.517.618.018.118.218.318.418.5-18.626.026.1TP
aaaaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Opera

99.5-9.610.0-10.110.510.61111.111.511.61212.11516171819202122232425262728293031323334353637383940414243444546474849505152535455565758606263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122
nnaaaaaaaaaaaaaaaaaaaaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Safari on iOS

3.24.0-4.14.2-4.35.0-5.16.0-6.17.0-7.188.1-8.49.0-9.29.310.0-10.210.311.0-11.211.3-11.412.0-12.112.2-12.513.0-13.113.213.313.4-13.714.0-14.414.5-14.815.0-15.115.2-15.315.415.515.6-15.816.016.116.216.316.416.516.6-16.717.017.117.217.317.417.517.6-17.718.018.118.218.318.418.5-18.626.026.1
aaaaaaaaaaaayyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

Opera Mini

all
a

Android Browser

2.12.22.3344.14.2-4.34.44.4.3-4.4.4141
uuaaaaaaay

Blackberry Browser

710
aa

Opera Mobile

101111.111.51212.180
aaaaaay

Chrome for Android

141
y

Firefox for Android

143
y

IE Mobile

1011
ny

UC Browser for Android

15.5
y

Samsung Internet

45.0-5.46.2-6.47.2-7.48.29.210.111.1-11.212.013.014.015.016.017.018.019.0202122232425262728
ayyyyyyyyyyyyyyyyyyyyyyyy

QQ Browser

14.9
y

Baidu Browser

13.52
y

KaiOS Browser

2.53.0-3.1
yy

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