This JavaScript exception missing = in const declaration occurs if a const is declared and value is not provided(like const ABC_DEF;). Need to provide the value in same statement (const ABC_DEF = ‘#ee0’).
Message:
SyntaxError: Const must be initialized (Edge) SyntaxError: missing = in const declaration (Firefox) SyntaxError: Missing initializer in const declaration (Chrome)
Error Type:
SyntaxError
Cause of Error: A constant value cannot be changed by the program while execution. It cannot be altered through re-assignment also.
Example 1: In this example, a const is declared but not initialized so the error has occurred.
HTML
<!DOCTYPE html> < html > < head > < title >Syntax Error</ title > </ head > < body > < script > const GFG; document.write(GFG); </ script > </ body > </ html > |
Output:
SyntaxError: Const must be initialized
Example 2: In this example, a const is declared and initialized later, so the error has occurred.
HTML
<!DOCTYPE html> < html > < head > < title >Syntax Error</ title > </ head > < body > < script > const INIT_VAL; // invalid statement INIT_VAL = 5; document.write(INIT_VAL); </ script > </ body > </ html > |
Output:
SyntaxError: Const must be initialized