转化为整型 parseInt()
var text = "123";
var number = parseInt(text);
console.log(number); // 输出:123
转化为浮点型 parseFloat()
var text = "3.14";
var number = parseFloat(text);
console.log(number); // 输出:3.14
更方便的转化 Number()
var text = "3.14";
var number = Number(text);
console.log(number); // 输出:3.14
var bool = true;
var number = Number(bool);
console.log(number); // 输出:1
bool = false;
number = Number(bool);
console.log(number); // 输出:0
var text = "abc";
var number = Number(text);
console.log(number); // 输出:NaN