Question: How to install underscore in nodeJS?
npm install underscore
Question: How to include underscore in nodeJS?
var _ = require('underscore');
Question: What is map in underscore? How to use? Give example?
Produces a new array of values by mapping each value in list through a function. The iterates is passed three arguments: the value, then the index (or key) of the iteration, and reference.
console.log(_.map([1, 2, 3], function(num){ return num * 2; })); //2, 4, 6
console.log(_.map([1, 2, 3], function(num){ return num * 3; })); //3,6,9
Question: Give an example of underscore.each?
console.log(_.each([1, 2, 3], function(value, key){
console.log(key+'>>'+value)
}));
Question: Give an example of underscore.reduce?
console.log(_.each([1, 2, 3], function(value, key){
console.log(key+'>>'+value)
}));
Question: Give an example of underscore.reduce?
console.log(_.each([1, 2, 3], function(value, key){
console.log(key+'>>'+value)
}));
Question: How to check if variable is empty OR Not?
_.isEmpty({});//true
_.isEmpty({'1'});//false
Question: How to create range values?
_.range(6);//[1,2,3,4,5,6]
Question: Can we use underscore for Web Client?
Yes, for this you need to include following JS.
https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js
Question: What are collections available in underscore?
each map reduce reduceRight find filter where findWhere reject every some contains invoke pluck max min sortBy groupBy indexBy countBy shuffle sample toArray size partition
Question: What are array are available in underscore?
first initial last rest compact flatten without union intersection difference uniq zip unzip object indexOf lastIndexOf sortedIndex findIndex findLastIndex range
Question: What functions are available in underscore?
bind bindAll partial memoize delay defer throttle debounce once after before wrap negate compose
