1. Disagreement
1.1 if condition
if (condition) {...} // execute if it is true, curly braces can be omitted for a single statement
if (condition) {...} else {...}// execute if if true, else execute else
if (condition 1) {...} else if (condition 2) {...} else {...} // if condition 1 is true, if condition 2 is true, otherwise execute else
1.2 switch
switch (parameter) {case fixed value 1: ... break; case fixed value 2: ... break; default: ... break;}
1.3 Ternary operation
expression? true: false
2. Cycle
2.1 for loop
for (let i = 0; i < x.length; i++) { ... } // continue跳过，break退出
2.2 while
while(expression) { ... } // continue to skip, break to exit
2.3 do while
do {... } while (expression) ; //continue to skip, break to exit
Remarks: use for for specific times, and while for unclear times