js conditional branch statement

Conditional branch statement

Conditional branch statements are also called switch statements.
Syntax:
switch (conditional expression) { case(expression): statement... break; case(expression): statement... break; default: statement... break; }

Execution process:
switch...case...statement

• During execution, the expression after the case and the expression after the switch will be congruently compared;
• If the result of the comparison is true,
  all the code behind the current case will be executed from the current case . Use break to end the switch statement
• If the comparison result is false, then continue to compare downward.
• If all the comparison results are false, only the
  switch statement and the if statement after the default statement are executed . The functions of the switch statement and the if statement are actually duplicated, and the two can be used instead

For example:
judge that the score is greater than or equal to 60 is qualified, and the score less than 60 is unqualified