Javascript 打字稿 - 将字符串转换为数字
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/42666343/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
typescript - convert string to number
提问by john
totalbalancetemp = (Number(this.balance)) + (Number(this.pastAmount));
My totalbalancetempis returning undefined whereas this.balanceis equal to 34 and this.pastAmountis equal to 23.
Mytotalbalancetemp返回 undefined 而this.balance等于 34this.pastAmount等于 23。
I have this in controller and displaying totalbalancetempusing exp in html
我在控制器中有这个并totalbalancetemp在 html 中使用 exp显示
回答by Mr. Polywhirl
Supply the proper type.
提供正确的类型。
let totalbalancetemp:number = balance + pastAmount
This will throw an error, because you are now guaranteeing that totalbalancetempwill be a number.
这将引发错误，因为您现在保证totalbalancetemp将是number.
The type String is not assignable to type 'number'
字符串类型不可分配给“数字”类型
Try the following:
请尝试以下操作：
let balance:string = '34',
pastAmount:string = '23',
totalbalancetemp:number = 0
totalbalancetemp = Number(balance) + Number(pastAmount)
alert(totalbalancetemp)回答by Senthil Kumar
var totalbalancetemp = null; this.balance = 34; this.pastAmount = 23;
totalbalancetemp = (Number(this.balance)) + (Number(this.pastAmount));
alert(totalbalancetemp);
-->totalbalancetemp - Define Variable (or) any type
-->totalbalancetemp - 定义变量（或）任何类型
回答by xird
totalbalancetemp should be replaced by this.totalbalancetemp if it's part of the angular 2 component
如果 totalbalancetemp 是 angular 2 组件的一部分，则应将其替换为 this.totalbalancetemp
回答by gildniy
Do a +this.balancein the .ts file or this.balance*1or this.balance/1on in the template file.
+this.balance在 .ts 文件中执行 athis.balance*1或this.balance/1在模板文件中执行。
