zoukankan
html css js c++ java
js变量前的+是什么意思
if (+value >= distance) {
这个+什么意思
可以理解为
Number(
value)
会将其按照Number函数的规则转换为数值或者NaN,规则大概如下:
Boolean:true返回1,false返回0
数据值,直接返回
null,返回0
undefined,返回NaN
对于字符串,将其转换为十进制数值,会忽略前面的0(16进制除外),空字符串返回0,浮点数会返回浮点数值。其他格式字符串(无论是否数字开头,返回NaN,字符串中好几个小数点,返回NaN)
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原文地址:https://www.cnblogs.com/chip-gan/p/13932281.html
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