The clever use of js with operators and or operators
- 2020-03-30 01:45:37
- OfStack
The following problem USES if else to realize the change of add_step under different conditions, and the result value of add_level is different:
var add_level = 0;
if(add_step == 5){
add_level = 1;
}
else if(add_step == 10){
add_level = 2;
}
else if(add_step == 12){
add_level = 3;
}
else if(add_step == 15){
add_level = 4;
}
else {
add_level = 0;
}
1) the above functions can also be achieved by switch:
var add_level = 0;
switch(add_step){
case 5 : add_level = 1;
break;
case 10 : add_level = 2;
break;
case 12 : add_level = 3;
break;
case 15 : add_level = 4;
break;
default : add_level = 0;
break;
2) Javasctipt is realized by || and && :
var add_level = (add_step==5 && 1) || (add_step==10 && 2) || (add_step==12 && 3) || (add_step==15 && 4) || 0;
3) the second writing method can also be abbreviated as:
var add_level={'5':1,'10':2,'12':3,'15':4}[add_step] || 0;