2022-06-16 work record --js- judge the number of digits in string type digits + judge the number of digits in numeric type digits + limit the text length (display n words at most, exceeding...)

One 、 Determine the number of digits in a string number

give an example ：

console.log('10'.length); // 2
console.log('120'.length); // 3

Two 、 Judge the number of digits of numerical type

Need to go through first Numeric number +'' take Numeric number convert to String number .

give an example ：

console.log((10+'').length); // 2
console.log((120+'').length); // 3

3、 ... and 、 Limit text length （ At most n A word , beyond ...）

/* text:  Text content  n:  Limit length  */
function limitTextLength(text,n) {
    
	return text.match(/[\u4E00-\[email protected]#$%^&*()_+-=.]/g).length>n?text.substring(0,n)+'…':text
}

limitTextLength(' It will be a great task for us ',6); // ' The great task will fall on …'
limitTextLength('Rabbits like carrots',9); // 'Rabbits l…'
limitTextLength(' Pink &&Rabbits like carrots',9); // ' Pink &&Rabbi…'

【 Add 】 Limit the format of text content according to project requirements , Stay if necessary 、 If not, delete .

\u4E00-\[email protected]#$%^&*()_+-=. Split into four parts from left to right ：

• \u4E00-\u9FA5（ Chinese characters ）
• a-zA-Z（ Case letters ）
• 0-9（ Numbers ）
• [email protected]#$%^&*()_+-=.（ Special characters ）