07-分支和循环详解

分支和循环详解

if判断

var age = 3;
if (age>3){   	//第一个判断
    alert("haha ");
}else if(age<5){ //第二个判断
	alert("kuwa~"");
}else {    		//否则,,
	alert("xixi~");
    }

while循环。避免程序死循环

while(age<100){
	age = age + 1;
    console.log(age)
 }

do{
    age = age + 1;
    console.log(age)
}while(age<100)

for循环

  for (let i = 0; i < 100; i++) {
        console.log(i);
    }

forEach循环

  var age=[12,3,123,4,5,78];
  age.forEach(function (value) {
      console.log(value);
  })

for…in(了解即可!还不如for循环呢…)

//for(var index in object){} 
var age=[12,3,123,4,5,78];
  for (var num in age){
      console.log(age[num])
  }