script分支语句

if

a = 1;if(a == 1){console.log("num is 1")}else if(a == 2){console.log("num is 2")}else{console.log("num is not 1 and is not 2")}

等号

console.log(1 == "1") //true//双等号只判断值是否相等

console.log(1 === "1")//false

//三等号判断值和类型是否同时相等

switch

num = 3;switch(num){case 1:console.log('a');break;case 2:console.log('b');break;case 3:console.log('c');break;default:console.log('find nothing');}

选择语句，当数量不多时，比判断语句好用