限制可變長度

Question

我想限制一個變量。如果它包含超過300個字母，則應該修剪，這樣只有300個字符。有什麼方法可以在jQuery中做到這一點？

Answer 1

只是pure的JavaScript：

myVar = myVar.substring(0, 300); 

Answer 2

// Assume really_long_string is over 300 characters long 
var really_long_string = "abcdefg..." 

// Your new string, truncated to fit your desired length 
var shortened_string = really_long_string.substring(0, 300) 

Answer 3

JavaScript有這兩種本地方法...

string.substring(from, to) 

variable_name = variable_name.substring(0,300) 

和

string.substr(start,length) 

variable_name = variable_name.substr(0,300) 

他們都應該做的伎倆。

編輯：作爲@freakish建議

string.slice(beginslice, endSlice) 

variable_name = variable_name.slice(0,300) 

注：substring和slice大致相同，不同之處slice可以接受（相對於字符串的末尾）負索引，其中爲substring可以」噸。另外，substr將長度作爲第二個參數。

Answer 4

無需jQuery的 - 只是用在子JS應該做的伎倆

var originalString = 'This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... This content is more than 300 characters... '; 

document.write(originalString.substring(0, 300));