只作用于最近的语句
if(true) console.log('a')
console.log('b')
assert
a
b
if(false) console.log('c')
console.log('f')
assert
f
if(false)
console.log('c')
console.log('f')
assert
f
只作用于最近的语句
if(true) console.log('a')
console.log('b')
assert
a
b
if(false) console.log('c')
console.log('f')
assert
f
if(false)
console.log('c')
console.log('f')
assert
f