Single branch
if(){}
if statement name
() Single branch condition, logic point, Boolean value
{} The code to be executed when the logic point is true
var m = "78";
if(m > 77 ){
console.log("吃东西");
}
Double branch
if(){}else{}
if statement name
() Branch condition, logic point, boolean
{} code to be executed when the logic point is true,
part of the statement name
{} to be executed when the logic point is false Code
var n=9;
if(n%2 ===0){
console.log(n +"是偶数")
}
else{
console.log(n + "是奇数")
}
var n=4;
if(n%2 === 0){
console.log(n+ "是偶数")
}
else{
console.log(n+ "是奇数")
}
Multi-branch simulation of dual branch
Exam scores: 60-fail, 60+pass, 70+ fair, 80+ good, 90+ excellent, 100 very good
var n = 110 ;
if(n>=0&&n<60){
console.log(n+ "不及格")
}
else if(n>=60&&n<70)
{
console.log(n+ "及格")
}
else if(n>=70&&n<80){
console.log(n+ "良好")
}
else if(n>=80&&n<90){
console.log(n+ "优秀")
}
else if(n>=90&&n<100){
console.log(n+ "非常优秀")
}
else {
成绩错误
}
Multi-branch
switch(){}
switch statement name
() value or variable to be judged
{} branch body, statement to be executed in the entire branch
var m = 10;
switch(m){
case 0:
console.log("星期日");break;
case 1:
console.log("星期一");break;
case 2:
console.log("星期二");break;
case 3:
console.log("星期三");break;
case 4:
console.log("星期四");break;
case 5:
console.log("星期五");break;
case 6:
console.log("星期六");break;
default:
console.log("输入错误");break;
}